Pellegrini is already looking beyond Tuesday night to a run of games that he hopes will prove themselves to be just as important.
"We have 30 points from now until the end of the season to play for and we'll try to win the most amount of points we can," said Pellegrini.
"Maybe we can win at Manchester United and then lose here against Southampton and the title is gone so every game has the same importance and we must start against Manchester United and hope we do as well as we did against Fulham.
"It's always important for a new manager in his first season here in the Premier League to win the derby.
"'Maybe if you don't win here at home [against United] the fans are not so happy so that first was one of the important games of the season. I know for the fans to beat United is special."