Manchester City manager Manuel Pellegrini says the 3-0 win at rivals Manchester United was "important psychologically" in the title race.
City opened the scoring inside a minute through Edin Dzeko and ran out easy winners to close to within three points of Premier League leaders Chelsea.
"It was important because it was one of the three big matches we still have to play," Pellegrini said.
"I am not thinking about the title but we fight with the other three teams."
City have two games in hand on Chelsea and face fourth-placed Arsenal at Emirates Stadium on Saturday. They travel to Liverpool - currently in third - on Sunday, 13 April.
If they win their remaining games, City will be champions but Pellegrini did not accept that his side are favourites to regain the title they won in 2012.
"We continue recovering points on Chelsea, Liverpool and Arsenal, so it was very important to keep adding points," Pellegrini said.
"It was an important win against a great team like Manchester United. You'll never know how many points you'll need."
Dzeko added a second with a volley from a corner after the break and Yaya Toure drilled home in stoppage time to cap a fifth City victory in the last six meetings with United.
"Manchester is and will always be blue," Toure wrote on Twitter.
Dzeko, who has scored five goals in six appearances against United, told Sky Sports: "This game could be crucial at the end of the season.
"We wanted to start playing our game from the first minute and trying to score an early goal, which we did. Then it was all about us. We were amazing."
Despite being third choice behind Sergio Aguero and Alvaro Negredo for most of the season, Bosnia striker Dzeko has scored 20 goals in all competitions for City this season.
"All of the players have different moments in their performance in the year," Pellegrini said.
"With Edin, maybe at the beginning of the season he didn't start very well, but he has improved a lot."