Chelsea are still some way behind United in the title race, trailing by 11 points, but Benitez is not ruling anything out.
Asked if he will tell his players they can still win the league, Benitez said: "We will see after two or three more games.
"You could see the team had confidence in themselves, they believed, and that was there to the end.
"They had good movements, created chances. Now we have to sustain this run and it will be easier for me to say we can compete."