United were on the verge of failing to score for a third consecutive European home game until the Belgian turned and shot into the far corner, provoking Jose Mourinho to throw a box of water bottles to the ground in a mixture of joy and relief.
Mourinho did have some kind words to say about David De Gea however.
"It reminded me very much of the Seville game previous year".
"Frustration, I was not unhappy with the players, not at all, frustrated we couldn't score, yes, but my players were very exhausted in end and that's what I love, it means they gave everything".
"But really I had a conversation with the coach about it and I said: 'Listen, it's been a long year and also with the World Cup, I felt a bit exhausted'".
"Is about us as a team, is very hard for us to score goals".
David de Gea made a miraculous save to swipe a deflected ball off the line, preventing a potentially disastrous opener for the visitors.
Though United did emerge victorious on Tuesday, they could have easily gone a goal down in the second half.
"Realistically, to be in the last 16 in this group is an achievement, not a big one, not a fantastic one, but is an achievement".
"Let me send a message to my lovers and say I play Champions League for 14 years and qualify 14 times", he said. The seasons I didn't play in the Champions League, I won the Europa League. "So just curiosity for my lovers and the lovers of the stats". Rashford certainly did not have his best game but there was no need from this reaction from his manager, a reaction that certainly will not have helped the young forward. I would invite that people to sit on the bench as managers.
"I think the mood is good. I don't think it was really aimed as much at us as individuals", Shaw said.
Mourinho bristled when quizzed about that selection before kick-off and pointed to onlookers "always asking" him to play Marcus Rashford - a player who missed a fine chance in the opening minutes and numerous more over the course of the night. "For the ones that have a nice life, it's different".
It is not just critics that irritate Mourinho but questions, too, having raised eyebrows before the game by dropping Romelu Lukaku and Paul Pogba to the bench, with Alexis Sanchez missing out entirely. Gary Lineker said in the BT Sport studio as a former centre-forward.
Key stat: Fellaini has now scored nine match-winning goals for Manchester United. "Because I would go through a brick wall for him and he knows that".