But the Blues boss admitted his own side also needed to win all five of their remaining games to retain their crown.
Chelsea 3 Birmingham 1: Read Laura Williamson's match report from Stamford Bridge
Winning feeling: Chelsea kept their title hopes alive with a 3-1 win over Birmingham
Chelsea took a small step towards the most improbable of late surges by beating Birmingham 3-1 at Stamford Bridge to leapfrog ailing Arsenal into second place and close to within six points of United.
The leaders are still firm favourites to finish top, but have to play both of their closest challengers in the next three games.
Belief: Chelsea manager Carlo Ancelotti has every hope his team will win the title
Ancelotti said: 'To win the title we'll need less points than last season. We won it with 86 last season. Now, with 80 points, United can win the title. They need 10 points.'
He added: 'In football, I learned that everything can happen in the game right up to the final whistle. You can win the title in the last minute and you can lose the title in the last minute.
Benched, again: Fernando Torres made little impact as a second half substitute
'If we thought that one month ago we'd have a little chance to come back to fight for the title, I think that everyone could have said we were crazy.
'Now we are happy tonight because we've reached second place. We await to see what happens in the next five games.'
Haven't got a Kalou how to deal with him: Birmingham sturggled to contain Salomon Kalou, who scored a stunning second goal
However, Ancelotti refused to look too far ahead, saying: 'Our aim is to try and win every game. After that, we can see our results and our position in the table.
'Six points at this stage with five games to go will not be easy, but we don't have to think we can or can't do this.'
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