Bruno Fernandes’ second-minute penalty and Luke Shaw’s second-half strike ensured a 2-0 win for Ole Gunnar Solskjaer’s second-placed team as they cut the gap to City to 11 points.
With 10 games remaining, United will be unable to catch Pep Guardiola’s side, according to Keane. But the former Red Devils midfielder was full of praise for his old club’s performance at the Etihad Stadium.
READ MORE: How Shaw became United’s second-most player
“It was vital they kept that momentum up,” Keane told Sky Sports. “We said earlier in the season, could they be the best of the rest? And I think they’ve proven today that they can be. Excellent.
“Ole simplified everything, back to passing it forward quickly, counter-attack, space… everything panned out the way he hoped.
“They had a bit of swagger about them. They weren’t cocky. I know they had a bit of a helping hand, but you still have to take advantage of that and they showed a bit of character.
“It was a great day for United. Did we think they would win 2-0 this morning? Probably not.
“But you felt there was a performance coming despite the criticism they’ve had for the last couple of performances. Today was perfect for them, they took full advantage and it was a proper Manchester United performance.”
United’s next league game sees them host high-flying West Ham on 14 March, with a Europa League last-16 first leg against AC Milan taking place first on 11 March.