Manchester United emerged from the derby with bragging rights after ending the Premier League leaders’ 21-match winning run in all competitions.
United went into the game as clear underdogs after failing to score in their previous three games but was awarded a penalty inside the first minute when Anthony Martial was felled in the box by Gabriel Jesus.
Bruno Fernandes dispatched from the spot, despite Ederson getting a strong hand to his penalty, before City grew into the game as the first half went on, dominating in the build-up to the interval.
United flew out of the traps in the second half, though, with the in-form Luke Shaw finding the bottom corner after a driving run down the left flank and a one-two with Marcus Rashford.
The result takes United up to second in the table, 11 points behind City with 10 league games to play.
When asked about catching up with Man City, Solskjaer, “No, we just take one game time. They are too far ahead to think we can catch them. They have been excellent. Even today they put you under so much pressure.”
While reacting to the out come of the game, Guardiola said, ”Congratulations Manchester United first of all.
“Ten games left, now arrive the important part of the season. The last 10 games are important and we start next Wednesday. We will try to win as many games as possible to be champions.
“Against West Ham we played much, much worse than today. Against West Ham, we didn’t deserve to win and maybe today we didn’t deserve to lose. We were not good in front of goal, our strikers were not brilliant today but it happens.”