Jose Mourinho has branded Arsene Wenger a "specialist in failure" as he hit back at the Arsenal manager for suggesting the title was "Chelsea's to lose".
"He is a specialist in failure. I'm not. 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," the Chelsea manager said.
"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 London and not come back."
Chelsea currently top the Premier League table sitting just one point above Arsenal.
Arsene Wenger has suffered a difficult few days with his team getting knocked out of the FA Cup, having an angry exchange with journalists at a press conference and seeing his Arsenal side lose to Bayern Munich last night.
But the French manager has received some unlikely support from the Deputy Prime Minister Nick Clegg.
The Liberal Democrat leader and Gunners fan was asked on LBC Radio what he thought of Arsenal's defeat last night and said: "I'm heartbroken ... I know what it's like to lead a team through ups and downs."
He added: "The guy (Wenger) has achieved amazing things in 16 years and he has got an incredibly young and talented team ... to now start all blaming it on him, I think might make things worse at Arsenal."
Arsenal manager Arsene Wenger has joined the growing band who believe Spain have become a boring team. Commenting on Eurosport.com, Mr Wenger wrote:
"These guys are more than outstanding footballers; they are really intelligent and they are winners. I want to give them credit for that. However, they have betrayed their philosophy and turned it into something more negative.
"They are still absolutely outstanding, but they have less penetration than before."