United sealed a 3-1 aggregate win by winning 2-1 at Old Trafford on Tuesday night.
“Our performance was not so bad but in the two games United deserved to win,” Ancelotti told Sky Sports.
“The game was in balance until the end. Also we played with 10 men.
“We came back into the game with 10 men but in the end it was not enough.
“I think we had good control of the game for the first 25 minutes of the first half (but) we were not able to score.
“We had some opportunities to score but the end of the first half when they scored made it more difficult for us.”
Didier Drogba replaced Fernando Torres at half-time and scored Chelsea’s only goal in the game.
Ancelotti said: “Drogba had a fantastic second half, using power and ability and scoring a goal.”
