Of course it had to be him.
Of course it had to be them.
The side once famed for their last-ditch goals, nicking wins at the death, salvaging all three points when perhaps their performance deserved less - a knack which has somewhat diminished in years gone by.
Here they found just what was required.
At times it looked out of reach and in some ways desperate, with Ole Gunnar Solskjaer throwing Edinson Cavani and Jesse Lingard on to try and overcome a Villarreal side who had more than enough chances to win the game.
But Bruno Fernandes' reaction after the game suggests - on the field at least - that United knew Cristiano Ronaldo's injury-time winner was always going to come.
"I always had the feeling we would win the game," Fernandes told BT Sport. "When they score I feel that we could come into the game and turn it around it around.
"After the goal of Alex [Telles] everyone felt the atmosphere it was incredible, the push from the fans was incredible, some big saves from David [de Gea] who helps a lot to keep the result at 1-1.
"At the end, Cristiano as we always say strikers have that feeling to score and he has done it once again."
It was in many ways possibly Ronaldo's worst performance since his well-received return to Manchester last month.
The Portuguese striker barely got a sniff of goal all evening and question marks over United and Solskjaer's problems looked to be worsening when Paco Alcacer put the visitors ahead shortly after half-time.
Until that point United had been largely second best, and it was only through Villarreal's poor finishing that they weren't already behind.
But Alex Telles' stunning volley pulled them back in contention, and immediately the United faithful inside Old Trafford smelt blood.
The fans were willing United on, sensing there was another goal in it.
Lingard was denied by a great save from Geronimo Rulli in the Villarreal goal late on, which looked to be United's final chance.
But the United midfielder once again provided a vital contribution to tee up Ronaldo in the 95th minute to fire past Rulli from close range and send Old Trafford into raptures.
With their legendary manager in the stands, this was Fergie time at its best.
Solskjaer may even have thought twice about taking Ronaldo off at one stage - though that thought may only have been fleeting.
The man simply breathes goals. And with Cavani up top alongside him, it was almost written that one of them was going to find the all-important winner - no matter how long it was going to take.
"We finished the game with two strikers so we know any ball in the box they will be alive for everything, Eddy and Cristiano always alive," Fernandes continued.
"The defender drops or the goalkeeper drops we know we can score at any moment that's why we do more crosses when Eddy comes on and we got the goal, three amazing and three important points."
It wasn't vintage United and there will be many things for Solskjaer to pick apart on the training ground before the weekend.
But Ronaldo's presence has given them that belief they can score at any time - which is always a dangerous prospect.
