Paul Pogba and Zlatan Ibrahimovic have had a near telepathic understanding this season and combined again for United's winner at Blackburn.
An unwanted replay looked set to be added to our hectic and ever-increasing fixture list but the Reds marquee signings made the difference to send us through to the quarter finals.
The pair have proved United's go-to match winners on many other occasions this season - Swansea, West Brom and Palace to name but three - and linked up to devastating effect once more at Ewood Park.
United fell behind through Danny Graham's early opportunistic strike but quickly pulled level through the brilliance of Henrikh Mkhitaryan and composure of Marcus Rashford.
Named on the bench for the third FA Cup tie in a row, Ibrahimovic and Pogba were summoned just after the hour mark in place of Jesse Lingard and Anthony Martial.
Jose had probably hoped he wouldn't need his big guns but they were sent on with a mission with the tie poised at 1-1 and duly delivered.
Pogba has really come into his own during United's excellent run of one defeat in 24 outings and his passing range, energy and pace lifted the Reds from their slumber.
In almost a carbon copy of the winner at Palace in December, he picked out Ibra with an inch-perfect pass for Zlatan to do what he does best.
That one moment of quality proved enough for United to progress, but it was by no means the only decisive contribution from the Reds summer acquisitions.
Mkhitaryan controlled much of the match with his intricate passing, elusive movement and pacy, incisive forward play.
The Armenian started in the number ten role and showed his class throughout with a majestic individual performance.
United's man of the match set up Marcus Rashford's equaliser with an exquisite, outside-of-the-foot ball that opened up Blackburn's defensive line.
Far from the gamble many thought Jose had taken, the addition of Ibra to the squad has proved to best our best for years and nothing short of a masterstroke.
For a 35-year-old to hit 24 goals in his first season in England is outstanding, but his off-the-field contribution has not gone unnoticed either.
Rashford and Anthony Martial have said that the Swede has been a role model for the younger players and that working with him is an invaluable learning curve.
There remains some questions over an extended Old Trafford stay for Zlatan but we should look to get him signed up as quickly as possible.