Chelsea have now scored 93 goals this season and have eight more than United in terms of goal difference, but Ancelotti feels they need wins against Liverpool and Wigan for a first title since 2006.
A hat-trick from Ivorian striker Salomon Kalou, a brace from Frank Lampard, including a penalty, and late goals from substitute Daniel Sturridge and Florent Malouda did the job for Chelsea on Sunday and Ancelotti was naturally delighted.
"We maintained good discipline on the pitch for 90 minutes," he said. "We played well and quickly, and for that I am happy.
"I told my players at half-time to continue to play. Goal difference was not important for this - we have scored a lot of goals this season in the Premier League.
"But it won't come down to goal difference to decide it. There will be one team that arrives in first place and another who arrives in second place.
"We have scored a lot of goals this season, I think it's 93 in the Premier League now, and that's a very good record for us.
"It will be very difficult at Liverpool. But it is in our hands. Liverpool are a fantastic team still going for fourth place.
"It's ours to lose. But that's a good thing. To have a title in our own hands is a good thing.
"Our destiny is in our hands, so now I am quiet and calm. I am happy because we played very well. It was an important game. We needed to come back to the top of the league after Manchester United's win, and we played very well.
"There was a bit of pressure on us before the game but the team were focused and put in a fantastic performance.
"But we don't need to send a message to the other teams. This is a good message for us. We needed a good reaction after the defeat at Tottenham, and we did that. This is a good message for us, no one else.
"I think United will be able to win their games. They have Sunderland and Stoke, and every game is a different story, but our aim is to win two games.
"I know that, if we win two games, we are champions. I hope we play against Liverpool like we played today.
"They will want to fight against us to reach fourth. That's a very important position for the future of their club."
Ancelotti, who threatened to go to the movies instead of watching Manchester United on Saturday, revealed he went for a walk in the park instead.
"I walked in the park yesterday," said Ancelotti. "Maybe Sir Alex Ferguson went to see a movie today."