Ole Gunnar Solskjaer hailed super-sub Edinson Cavani's role in Manchester United's "excellent" performance to give them a last-gasp win at Southampton.
Cavani was introduced at the break by Solskjaer with United 2-0 down at St Mary's, and still had time to produce a man-of-the-match performance by making one and scoring two goals in their turnaround victory - including a 92nd-minute winner to lift his new side into the top half.
The manager insisted he had been happy with all aspects of his side's performance and reserved special praise for the the Uruguayan summer signing, who has now scored three Premier League goals across just 127 minutes of league football.
"I thought we were excellent all day long," said Solskjaer. "We played some fantastic football, created chances, five or six opportunities, and they have James Ward-Prowse. You can't stop him. You hope you don't give set plays away because he has got that quality, and you can't blame anyone.
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"[Cavani] is a centre forward who thrives on crosses and delivery in the box. He has been in there for so many years, and he's made a difference today.
"Of course, it's great to get three points in the way we did it, the comeback, the tradition of this club, it is something this team is getting better at as well."
Solskjaer did aim one note of frustration at the 33-year-old, however, whose introduction was halted by a late decision to change his boots - meaning United kicked off for the second half with only 10 men on the pitch.
The United boss, who once held the record for Premier League goals scored as a substitute, said: "He probably wasn't able to warm up on the pitch, and then suddenly when he realised he needed bigger studs, I'm happy he did.
"He'll have to learn on that one, you have to be ready as a sub - I know more about that than anyone!"
Goalkeeper David de Gea was also withdrawn at half-time at Southampton after suffering a knee injury.
De Gea banged his left knee on the post in his failed attempt to keep out James Ward-Prowse's free-kick which doubled Southampton's lead late in the first half.
Solskjaer admitted he was hopeful De Gea would be available for Wednesday's important Champions League clash with Paris Saint-Germain - but took the opportunity to praise the Spaniard's stand-in.
"Let's have a little check on [De Gea]," Solskjaer told Sky Sports. "Hopefully he will be ok for Wednesday but I'm not sure."
"Dean played well though. He is a 'keeper who is used to being vocal. He wants to organise his team. He didn't have big saves to make but he was safe with his hands."
Keane: Cavani answered his critics today
Former Manchester United captain Roy Keane told Sky Sports that Cavani, whose arrival on Transfer Deadline Day had been questioned after making only seven Ligue 1 starts for PSG last season, had done enough to prove a point with his brace against Southampton.
He said: "It was always a gamble when he came to club. People were doubting did he have the hunger and desire.
"We've seen proof of it today. He could prove a huge signing for Manchester United."
On the forward's winning goal, ex-Chelsea and Leeds forward Jimmy Floyd Hasselbaink added: "It's his movement. Every young striker has to look at him. He anticipates; he is always on the move.
"He knows where the ball is coming. Yes, it is a good delivery but it's all about the movement."
Hasenhuttl: Cavani made the difference
Ralph Hasenhuttl's side began the game hoping to end the day as high as second in the Premier League table, but are now two games without a win on the back of dropping two points from a winning position against Wolves on Monday Night Football before Sunday's defeat.
He told Sky Sports: "The subs made a difference today, especially Cavani. It's hard to defend, and then if you have no pressure on the ball anymore, and sitting deep, it is difficult against this team.
"They have good deep runs, it's difficult to defend, so in the end it wasn't enough for one point. I don't know if we'd deserve enough for one point, for the first half yes, we were the much better team, but they have quality. Maybe we were a bit unlucky, but I don't want to see heads being down today.
"I have seen a team that was amazing with the ball and against it for long periods. We let them struggle for a long time, it's not always enough, but today it was a good signal of how we are in our development."