London - Andre Villas-Boas has been sacked by Chelsea after less than a season in charge at Stamford Bridge, the Premier League club announced in a statement on their website on Sunday.
Former Chelsea midfielder Roberto Di Matteo, who had been working as Villas-Boas's assistant, has been appointed interim manager until the end of the season.
Villas-Boas, who arrived from Porto in June 2011, has paid the price for a dismal run of results that left Chelsea in fifth place and on the verge of elimination from this season's Champions League after a 3-1 defeat at Napoli in the last 16 first leg.
The 34-year-old also had strained relationships with several of Chelsea's senior stars, including England midfielder Frank Lampard, and a woeful run of results - including just one win in their last seven matches and only three from their last 12 in the League - forced owner Roman Abramovich to act.
The final straw came on Saturday as the Blues suffered a lacklustre 1-0 defeat at West Bromwich Albion thanks to a late winner from Garth McAuley.
"Andre Villas-Boas has parted company with Chelsea Football Club today," the Chelsea statement read.
"The board would like to record our gratitude for his work and express our disappointment that the relationship has ended so early.
"Unfortunately the results and performances of the team have not been good enough and were showing no signs of improving at a key time in the season.
"The club is still competing in the latter stages of the Champions League and the FA Cup, as well as challenging for a top-four spot in the Premier League, and we aim to remain as competitive as possible on all fronts.
"With that in mind we felt our only option was to make a change at this time.
"With immediate effect Roberto Di Matteo has been appointed first team coach on an interim basis until the end of the season."