- Fellow substitute Alexis Sanchez then turned provider to let Marcus Rashford slip in a second goal
- Fourth win in a row under Ole Gunnar Solskjaer moves United six points off the Premier League top four
Ole Gunnar Solskjaer will forever be celebrated as Manchester United's ultimate supersub. In management, too, it would appear he has the knack of influencing a contest with a timely change.
Never, though, did it take him just 38 seconds to strike after his introduction. That is what Romelu Lukaku did here to set up a victory which sees his manager become only the second in the club's history to win their first four league games in charge. Sir Matt Busby is the other, and that's not bad company to keep a couple of weeks into the job.
Lukaku needed just two minutes to score after coming on during Sunday's 4-1 victory over Bournemouth. But he wasn't hanging around this time.
The Belgian had watched for 63 minutes as his team-mates toiled, a shadow of the side who had smashed 12 goals in three games since being freed of Jose Mourinho's smothering and impeding presence.
United had a free-kick 25 yards from goal as Lukaku - joined by fellow sub Alexis Sanchez - trotted into position. Marcus Rashford took aim and, when his dipping effort bounced just in front of Martin Dubravka, Lukaku pounced to take advantage of the goalkeeper's spill.
It was a relief for Solskjaer - whose team had been second best against Rafa Benitez's well-drilled hosts before the double change - and Sanchez laid on the game-clinching second for Rashford 10 minutes from the end.
Solskjaer's celebration in front of the travelling fans on full-time told of an interim appointment who wants more, a desire to remain that he later confirmed.
But the Norwegian will need to pass sterner tests than this before he is seriously considered for a permanent stay. His three previous opponents - Cardiff, Huddersfield and Bournemouth - had provided the kindest of introductions, do not forget.