Goals by Anthony Martial and Scott McTominay sealed the win for United, but Ederson was at fault for both United goals and almost gifted them another.
The Brazilian allowed Martial's shot to squirm under him for the first and then threw the ball straight to McTominay for the second in stoppage time, but Guardiola refused to point the finger of blame at his stopper.
Guardiola said: "He's an extraordinary keeper. That's the only thing I can say. It's part of the game so next time he's going to do better."
City have now lost seven games in a disappointing title defence and their latest defeat means Liverpool now need only six points from their remaining nine games to take their crown.
Despite that, Guardiola was not too downbeat about the performance, disagreeing with the assessment of midfielder Bernardo Silva that it was "not acceptable".
Silva was critical of the performance and season as a whole telling Sky Sports that a team like City cannot lose so many games in a season.
However Guardiola had a different view of things, saying: "I don't agree with Bernardo. Over 90 minutes we played really well. In the first half we need to be a little bit more aggressive in the final third but in the second half we did it a little bit better. In general we played well but congratulations United on the victory."
City were without the influential Kevin De Bruyne for the clash but Guardiola did not use that as an excuse, saying they have managed to cope in the past few seasons with the loss of key players.
City are back in Premier League action on Wednesday night when they take on Arsenal.