United overcame a spirited Southampton side in the EFL Cup final despite a largely disappointing performance which was rescued by two goal inspiration Zlatan.
Jose Mourinho and the 35-year-old Swede are now the two central figures taking United forward.
Jose's move to bring Ibra to Old Trafford on a free transfer from PSG - surely the best such move the Premier League has ever seen - was strategic and wise.
One of Jose's first moves after his appointment was to summon the Swedish veteran to Manchester despite the questions and grumblings about his age and lack of pace.
Jose knew United needed an inspirational talisman to set the standard for a disillusioned squad increasingly accustomed to frequent upheaval and instability.
Zlatan is a personality of equal stature and confidence, had a lot to prove having never played in England and is the world class match-winner we'd been crying out for.
Everything Ibra does have echoes of "The King" Eric Cantona - his enigmatic and languid style, his charismatic persona and his understated influence on the younger members of the squad.
He scored with a header on his United debut at Wembley against Leicester back in August and again came up with the goods when we needed it most.
Once again, this was his playground, his platform, his show.
How we needed Ibrahimovic desperately on Sunday because for long periods United were ragged, disorganised and on the back foot against a vibrant and energetic Southampton side.
He once again proved indispensable and made the decisive contribution to clinch a cup final that United did not deserve to win.
Thoroughly unconvincing we may have been, but Mourinho teams find a way to get the job done and so it proved as Ibra powered home an 87th-minute header.
He had earlier put United in front, albeit undeservedly, and then capped off another man of the match display with his late winner to seal a remarkable 32nd trophy of his career.
If this EFL Cup win is to be the catalyst for another period of success at Old Trafford, Ibrahimovic's continued presence will be essential.
United will never again be the dominant, trophy-winning juggernaut that we were under Sir Alex, no side will ever do that again in today's ever-evolving world of professional football.
But, if we're to get anywhere near that status again, Ibra is the man integral to Jose's plans, despite being in the twilight of his illustrious career.
With United still in contention for a possible cup treble, Ibra continues to be this side's inspirational figurehead and leader of the attack.
Louis van Gaal led United to FA Cup success in May and was then replaced almost immediately by Jose Mourinho.
That cup victory felt like the end of a story but our fifth League Cup win - for all its good fortune - had the sense of a new chapter.
Mourinho claimed the season's first major trophy as he became the first United boss to win silverware in his maiden campaign in charge.
The Portuguese drew level with his illustrious predecessors Sir Alex and Brian Clough as he lifted the League Cup for a fourth time
History suggests that winning this trophy leads to bigger things.
A league title - and then the double - followed the 1992 League Cup win over Nottingham Forest.
The success of Sir Alex's 2008 vintage can be traced back to the 4-0 win over Wigan in the final two years previously, which marked the first silverware for the emerging talents of Messers Ronaldo and Rooney.
This competition is where it all began for Jose, too, with the first of his triumphs back in 2005 during his first season in England with Chelsea.
As with United's victory a year later, it sparked a new era of dominance for the west London side and the Portuguese will demand the same at United.
Success breeds success and in a few years time this could be earmarked as the moment that kick-started something special.
Mourinho was bought to United as the man to revive our fortunes after a depressing and dismal three seasons of chaotic upheaval under David Moyes and Van Gaal.
The joyless existence post-Fergie needed change and in Jose we finally have a silver-laden manager to relish and embrace our history rather than shrink from it.
Seven months after his appointment, it's a good start for the serial winner but he will want more, with United still in contention to add the FA Cup and Europa League trophies to the cabinet.
An FA Cup win was not enough to save Van Gaal's job, so it figures that a solitary EFL Cup cannot be considered as the limit of the club's ambitions.
Whilst trophy wins provide success and satisfaction, Mourinho's primary ambition must be to lead the team back into the Champions League.
After the world record purchase of Paul Pogba and the Ibra coup, a return to Europe's top table is surely the minimum requirement.
Mourinho looked downbeat throughout Sunday's dramatic denouement because of the modest prize on offer and ragged performance by his side.
He will be aware that there's still a long way to go, but this cup win was another step on the road to our recovery since he took over.
Zlatan Ibrahimovic popped up with a late winner after spirited Southampton had fought back from 2-0 down in a thrilling EFL Cup final.
The big Swede headed home Ander Herrera's cross for his 26th goal of the season three minutes from time to deliver United's first major silverware under Jose Mourinho. He had earlier put United ahead with a free-kick, added to by Jesse Lingard's excellent strike, but the Reds were ragged for long periods and were pegged back by a vibrant and energetic Southampton side.
Manolo Gabbiadini, who had a controversial opener ruled out for offside, struck twice to equalise and now has four goals in three games since signing for the Saints from Napoli.
Saints fully deserved to force extra-time and looked set to do just that until Ibra, as he has done so often, had the decisive say.
Fraser Forster had saved well from Paul Pogba early on but then came the game's main talking point in the 11th minute.
Gabbiadini swept the ball home after Cedric Soares had cut it back, but the flag was up against the overlapping Ryan Bertrand and the goal was chalked off.
Saints made much of the early running but United took the lead, against the run of play, on 19 minutes.
Oriol Romeu brought down Herrera and Zlatan curled a sublime 25-yard free-kick over the wall and beyond the helpless Forster.
The goal did little to deter Saints who continued to press as David de Gea saved superbly to keep out James Ward-Prowse and Dusan Tadic.
Lingard had scored in both of his previous outings at Wembley and maintained that run once more this time out.
Anthony Martial, Juan Mata and Marcos Rojo combined for the latter to turn the ball infield to Lingard who finished well with a low effort.
Gabbiadini halved the deficit in first half stoppage time and then wiped out our advantage early in the second with a brilliantly instinctive strike.
Romeu headed against the post and Antonio Valencia rescued United with a brilliant clearance from Tadic's ball across goal.
De Gea saved well from Nathan Redmond and Ward-Prowse again went close from distance as United came under siege.
At the other end, Forster blocked well at the feet of Ibra, Lingard fired over and Marcus Rashford also went close as United upped the ante again in search of a winner in an increasingly end-to-end encounter.
Cruelly for Saints, it came with three minutes remaining when Herrera found Zlatan who headed in to seal a fifth League Cup triumph for United.
Overall team performance: 6/10
United Faithful Man of the Match: Zlatan Ibrahimovic. Who else.
Jose Mourinho leads United into their eighth League Cup final on Sunday at Wembley with a record-equalling feat at stake.
The Reds boss has never lost in the final of this competition having won it three times across his two spells at Chelsea - 2005, 2007 and 2015.
A fourth with United would match managerial greats Brian Clough and our own Sir Alex and seal a fifth success in this competition for the club.
United are boosted by the availability of Michael Carrick and Wayne Rooney also looks set to feature after he confirmed he's staying at United.
Jose said: "The important thing is not myself, it is the club and the wonderful fans, so we want to win this cup for them.
"Wayne did it (issue the statement) in the right moment, he was not ready to play against Saint-Etienne but no doubts he is involved in this game.
"Carrick is available, he is clever, very experienced and left the pitch in the right moment with a little feeling - Mkhitaryan and Jones are out so let's see and I can decide tomorrow.
"All the squad want to play in this final but it is not possible so it is a tough selection for me."
Southampton have reached Wembley without conceding a goal but will be without two key players for the final: injured captain and star man Virgil Van Dijk (ankle) and top scorer Charlie Austin (shoulder).
January signing Manolo Gabbiadini has scored twice in three games and will likely start up front with former Juve centre-back and free transfer Martin Caceres also set to feature.
United have seen off Northampton Town, cross-town rivals City, West Ham United and Hull to get this far.
Saints, meanwhile, have faced top flight opponents every step of the way, having overcome Palace, Sunderland, Arsenal and Liverpool in a memorable semi-final to reach a second ever League Cup final.
Their first came in 1979 (2-3 to Nottingham Forest), and they also ended up on the losing side in their last appearance in a final, the 2003 FA Cup against Arsenal.
If they're looking for an omen, however, then their only previous cup success should offer them one.
41 years ago, as a Second Division side, Saints lifted the 1976 FA Cup having beaten United 1-0 in one of the biggest final shocks in the competition's history.
Form guide: United D W W W W W Southampton W W L L L W
Match odds: United 4/5 Draw 5/1 Southampton 17/4
Referee: Andre Marriner
United have been paired with FC Rostov of Russia in the draw for the last 16 of the Europa League.
The first leg will be played at the Olimp2 stadium - a round trip of nearly 4,000 miles - on Thursday 9 March with the return meeting at Old Trafford a week later.
Sandwiched between the two matches is the FA Cup quarter final at Chelsea, scheduled for Monday 13 March with Middlesbrough at home in the league on the 19th.
Last season's runners up in the Russian Premier League, Rostov are the lowest ranked side left in the tournament but have enjoyed a best ever European campaign.
United finished second in Group A and reached this stage after an impressive 4-0 aggregate win over Ligue 1 outfit Saint-Etienne.
Having seen off Dutch giants Ajax in the play-offs, Rostov reached the Champions League group stage for the first time.
Drawn in the "Group of Death" alongside European heavyweights Atletico Madrid, Bayern Munich and PSV, their creditable third place finish sent them into the Europa League.
Under the tutelage of Austrian coach Ivan Daniliants, Rostov beat Carlo Ancelotti's side 3-2 in the home fixture and reached this stage with an impressive 5-1 aggregate win over Sparta Prague.
Last season's runners up in the Russian Premier League, Rostov are the lowest ranked side left in the tournament but have enjoyed a best ever European campaign.
United boss Jose described the tie as "bad in every aspect", and said:
"It's far to travel and it is difficult because the team is very defensive and physical, it is in a bad period for us.
"They had a very good Champions League campaign, they beat Ajax and Anderlecht in the qualifying and managed important results against Atletico and Bayern Munich, famous clubs, big clubs.
"They got third position to knock PSV out so it is a bad draw in every aspect but after Southampton and Bournemouth we focus on it and go for it."
Elsewhere, two of the tournament favourites will fail to progress beyond this round.
Lyon, who knocked out AZ Alkmaar 11-2, will face Roma and Schalke have been drawn with Monchengladbach in an all-German affair.
The full draw is: Celta Vigo v FC Krasnodar, APOEL v Anderlecht, Schalke 04 v Borussia Monchengladbach, Lyon v Roma, Rostov v United, Olympiakos v Besiktas, Gent v Genk, Ajax v Copenhagen
Southampton go into Sunday's EFL Cup final without injured captain and their best player Virgil Van Dijk.
The Saints centre back has been arguably the most impressive defender in the league this season and his absence will come as a major hit to their Wembley hopes.
Without him, Claude Puel's side lack anyone with the ability to be commanding and win the aerial duels - a shortcoming we should exploit.
Jack Stephens and Maya Yoshida did an admirable job as stand-ins in the win at Anfield, but Liverpool's possession-based passing game played into their hands.
Former Juve defender Martin Caceres has joined Southampton on a free until the end of the season but has hardly played in the last year and looks likely to start on the bench.
Zlatan Ibrahimovic will start up front and, in the likely absence of the injured Michael Carrick, Marouane Fellaini could play a key role.
Carrick's guile and fluidity contrasts starkly with that of Fellaini's style, but in the absence of the 35-year-old, Jose is likely to utilise the Belgian.
The in-form Belgian has been a key man in our run to Wembley, scoring what turned out to be the decisive goal in the semi final win over Hull.
He was also influential when United salvaged a late point against Liverpool in January.
The introduction of the 6ft 4 Fellaini unsettled Jurgen Klopp's side aerially and he proved the perfect foil for the 6ft 5 Ibra, as the two players combined for the latter's late leveller.
Fellaini was often pressed into service as a last-ditch target man by LVG and, as a result, the team often became predictable.
The addition of Zlatan into the team has seen dovetail perfectly with Fellaini, and Paul Pogba's impressive arsenal of weaponry has helped to play to the duo's strengths.
Ibra is the focal point, leader of our attack and the team's charismatic talisman.
He's already scored twice against Southampton this season so Saints will be all too aware of the threat he poses.
Stopping him from doing so again and cutting off the supply line is easier said than done - particularly without Van Dijk's leadership, positioning and heading ability
The key for United is to getting the ball up to Zlatan, then pushing players forward in support and running in behind to deliver it into the box.
Saints will sit deep, stay compact and force United to break them down so it is a tactic Mourinho is likely to use again at Wembley.
Jose Mourinho will lead United out for Sunday's EFL Cup final with Southampton knowing that victory will create a little piece of club folklore.
Mourinho has won the League Cup in each of his three full seasons at Chelsea and a fourth triumph, this time with United, would create another first in the club's illustrious history.
The Reds will meet Claude Puel's Southampton side - themselves looking to re-write the record books.
"The Saints" have never won the League Cup trophy and their only other major honour came back in 1976 when they beat United in the FA Cup final as a Second Division side.
No Reds manager - not even legendary knights Sirs Matt and Alex - have been able to win a trophy in their first season at the helm.
Dave Sexton is the only United manager to get anywhere near silverware of any description in his first campaign.
Even then, it was only a Charity Shield (which doesn't really count anyway) in 1977, shared after a 0-0 draw with Liverpool in the days before penalty shootouts.
Busby, who would go on to win 13 trophies at Old Trafford, including five First Division titles and a European Cup, had to wait until his third campaign for silverware - the FA Cup in 1948.
Sir Alex, British football's most successful ever boss, similarly endured a difficult three seasons at the helm before the FA Cup win in 1990.
History suggests that he may not have survived beyond that season had we not won that - a success which laid the benchmark for the phenomenal silver-gathering juggernaut that followed.
Three years on, and seven since he took over in 1986, the first of thirteen Premier League titles arrived in 1993.
Louis van Gaal delivered a domestic trophy in his second season last term but Jose has the opportunity to eclipse them all.
Seven months into a four-year contract, Jose has taken us into the first of three possible finals this season with United the only English team fighting on all four fronts.
He's stamped his authority and identity on the squad far quicker than LVG ever did and, if the talk is true, he looks set to be offered an new contract in the summer.
With the first major silverware of the season on offer, United are bidding for a fifth League Cup triumph to move joint second on the all time list of the competition's winners (Chelsea and Villa have five apiece).
Sunday's showpiece is the first of the Mourinho era at Old Trafford, but it almost certainly will not be the last.
