Manchester United manager Louis van Gaal described Marcus Rashford as a "real striker" after the 18-year-old scored the only goal to win the derby at Manchester City.
Rashford's cool finish, which came after he had tricked his way past Martin Demichelis, cut the gap between fourth-placed City and United to just a point.
The 16th-minute strike made him the youngest scorer in Manchester derbies during the Premier League era at 18 years and 141 days.
Van Gaal told Sky Sports: "He is a real striker. That's why I let him play in that position.
"He can make goals but also is an attacking point and runs the channels. Still, he is 18, so we have to wait and see how consistent he is."
Rashford thought he should have had a penalty when he was brought down by the struggling Demichelis, and Van Gaal said: "I think it was a penalty. We need video referees, I think."
The United boss praised his side for their speedy recovery from the Europa league exit to Liverpool on Thursday, adding: "A lot of players had cramp, but that is logical when you have played on Thursday.
"You saw what Liverpool did. They were 2-0 up then lost 2-3 [at Southampton] because they were not recovered.
"It was fantastic, what we did. We did it also against Arsenal. We have beaten Manchester City and it is not easy to win here.
"It was a long time ago that we won here, so it is for the fans as well."
Chris Smalling was again a commanding presence in defence for United and praised Rashford for making the difference.
The England defender said: "It's so refreshing to see a young lad who wants to run at defenders. If I was coming up against him, I'd know it'd be a difficult game."
Michael Carrick, meanwhile, said the win was "more than three points."
He added: "The position that we were in, in the league meant it was a must-win game. It gives us a bit of momentum."