Frank Lampard missed a penalty before the Ivory Coast international put the Citizens ahead and Carlos Tevez sealed three points with a powerful long-range effort.
Roberto Mancini’s side are now 12 points behind Premier League leaders Manchester United with 11 games left to play – and Touré admitted there can be no more slip-ups.
“We have 11 games remaining. In sport you never know what can happen in the future,” Touré told City’s website.
“We know that we have a more difficult schedule than them but we have to continue working to try to win as many matches as possible.
“We can’t let any more points slip away and that’s going to be key for the rest of the season.”
Toure conceded that it was far from a complete City performance against the Blues – but the midfielder was pleased to see his team-mates rise to the occasion and praised Joe Hart for his spot-kick save.
“I don’t think it was [our best performance of the season] but we needed a big performance. Chelsea are a big club with big players. The team worked fantastically well,” he added.
“It was very important. It was the turning point of the match because Lampard had never missed a penalty like that.
“It was a big performance by all the team.”
MORE: Latest Man Utd news
MORE: Latest Arsenal news
MORE: The latest football news