Roberto Mancini believes Chelsea are genuine title rivals to his Manchester City side.
The Premier League leaders head to Stamford Bridge on Monday 10 points clear of the Londoners.
But Mancini is wary of the threat posed by a team who won the title in 2010.
"I think they can win it," Mancini said. "They have 10 points less than us but we play two times against them and there are 24 games [left]."
He added: "The Premier League is very difficult and, in these two months, all the teams that play every three days will find it difficult.
"Last year Chelsea had a big lead [over Manchester United] but in the end United won the title by seven or eight points plus."
Mancini also believes Andre Villas-Boas is the right man to restore Chelsea to the pinnacle of English football, despite a difficult start to his reign.
The 34-year-old has suffered some mixed results on the pitch, while complaining of media persecution off it.
But the former Porto manager has Mancini's support.
"I think that has shown in the last year he is a good manager," the Italian said.
"He did well at Porto, he won trophies. Chelsea did well to get him.
"Carlo Ancelotti is a fantastic manager and I was sorry for him when Chelsea decided to sack him, but I think Villas-Boas is a good manager for them."
Villas-Boas realises the significance of his side's clash with City, and says they must "find a way" to beat the leaders.
"We don't know what is going to happen," Villas-Boas said.
"We know last year it was a difficult, tight game, solved in the last minutes with a 2-0 win [for Chelsea]."