The Blues moved into third spot behind Manchester United and Arsenal with an impressive 2-0 win that displaced Manchester City on Sunday.
David Luiz and Ramires got the goals as Chelsea continued their recent run but it may not be enough to keep their title.
“We have to try to win every game now,” said Ancelotti.
“There’ll be an international break and when the players come back, I’d like to see the same spirit and attitude.
“This was a very good result and performance. We are showing good spirit and good football and all the players are fit.
“It was important to put pressure up front and not concede. We could have done better in the final third in the first-half but after the break we did better and we put the pressure on.
“Luiz and Ramires - fantastic performances and fantastic goals. Ramires, in particular. He’s improving very well.
“Luiz’s goal was a surprise. Defensively, he worked with fantastic tempo for a long time and his performance was really good.”
Record signing Fernando Torres again failed to score but Ancelotti isn’t losing faith in the former Liverpool player.
He added: “He doesn’t have to lose his confidence. We have to be patient and so does he. The goal will arrive.”
City coach David Platt was disappointed with the result but still confident his team will secure a Champions League place for next season.
“Everybody’s dropping points so we’ll continue along our road but we want to stay within the top four,” said Platt.
“We’re disappointed because we defended pretty resolutely. The aim is to get as many points in our last eight games and we’ll see where that gets us. We should finish in the top four.”