Jose Mourinho has hit back in his on-running battle with Arsenal boss Arsene Wenger, accusing him of being a 'specialist in failure'.
The pair have been exchanging barbs in recent weeks, with the race for the Premier League title intensifying.
The Arsenal boss had earlier insisted that the title was Chelsea's to lose, and said that Mourinho's insistence that his team weren't title contenders is because of a "fear to fail."
The 'Special One' took exception to Wenger's comments, and speaking to reporters ahead of Chelsea's FA Cup clash with Manchester City responded: "He is a specialist in failure. I'm not."
He continued: "So if supposing he's right and I'm afraid of failure, it's because I don't fail many times. So maybe he's right. I'm not used to failing.
"But the reality is he's a specialist because, eight years without a piece of silverware, that's failure. If I did that in Chelsea I'd leave and not come back."
Just one point separates Chelsea and Arsenal at the top of the Premier League table, with Manchester City three points back from the Blues with a game in hand.
Mourinho and Wenger have shared a tetchy relationship in the past, dating back to when the Chelsea boss, in his first stint at Stamford Bridge, branded the Frenchman a 'voyeur'.
However Mourinho insisted the pair had buried the hatchet before their meeting at the Emirates Stadium earlier this season, which ended in a 0-0 draw.
Arsenal take on Liverpool in the FA Cup this weekend.