Andre Villas-Boas has been sacked by Chelsea, the club have confirmed.
The former Porto boss has been dismissed after the Blues slumped to a lacklustre 1-0 defeat to West Brom on Saturday. They currently lie in fifth place in the Premier League, three points behind Arsenal in the race for a top four finish.
Assistant manager Roberto Di Matteo will take charge of the first team on an interim basis until the end of the season.
A statement on the club's official website said: "Andre Villas-Boas has parted company with Chelsea Football Club today.
"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 Uefa 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."