Sunday's narrow victory proved to be Jose's most significant win since he took charge of United.
Henrikh Mkhitaryan's solitary strike ensured a first home league win since September and moved us to within six points of fourth place.
More importantly for Jose, it was the perfect tonic for United's big-game blues.
There have been echoes of his final months at Chelsea, but there is reason to believe we're heading in the right direction.
Tottenham came to Old Trafford having won only three of their past 12 games - a record virtually identical to ourselves - but Spurs are always a tough proposition and United were deserving winners.
The early years of Mourinho's career were built on results such as this, but we came into the game having picked up only two points from meetings with Manchester City, Chelsea and Arsenal.
We're sixth in the league, in the semi-finals of the EFL Cup and have progressed to the last 32 of the Europa League: a decent position to be in with almost half the season gone.
Last week's performance at Everton was one of our poorest of the season but I think we are making progress.
Mourinho's system seems to work, we attack, create chances, move the ball quickly and can score goals from anywhere and, as a fan of nearly 20 years now, it's these qualities that you associate with our club.
This was only the third time all season that Jose had picked an unchanged side from the previous league game, and while there are still questions over some areas of the team, it seems as though the boss is finally learning his best line-up.
Henrikh Mkhitaryan was again man of the match but there were impressive performances all over the pitch.
The Armenian was a constant threat and was at the heart of everything good going forward and Ander Herrera was his usual busy and bustling self.
He set up the goal for Mkhitaryan but, more than that, he quietly and effectively pulled the strings in midfield.
Herrera has now become one of this side's most important players and has flourished under Mourinho's tutelage.
This was far from an emphatic, gauntlet-throwing win, but it was a victory in Jose's image against a team who will be there or thereabouts come May.
Jose's start to life hasn't been the seamless transition he perhaps had hoped for, but this was exactly what he, and the team, needed.
After four frustrating months, finally there is something to build on and, with the busy festive fixtures just around the corner, it's vital we keep it going.