The 2-1 win at Everton courtesy of two Frank Lampard goals after Steven Pienaar's early opener for the hosts moved the Londoners into third in the Barclays Premier League.
They are just four points behind City and 11 adrift of leaders United, with a match in hand of both.
Benitez accepts confidence is high at Stamford Bridge but has told the players to focus on their next match, at home to struggling QPR.
"We have one game in hand but still we have to win this game," Benitez said. "Our idea is to think about one game at a time. We will see where we are after some games.
"I was really pleased with the Everton win because you could see the character of the players."