Andre Villas-Boas has been sacked as Chelsea manager.
Assistant boss Roberto Di Matteo has been installed as first-team coach on an interim basis until the end of the season, the club have announced.
Villas-Boas, who took over at Stamford Bridge last summer, had been under pressure following a series of poor results and reports of player unrest.
His team had won only three of their last 12 Premier League games and were plagued by defensive lapses during the 34-year-old’s troubled spell at the helm.
Chelsea are fifth in the table – in danger of missing out on next season’s Champions League – and Saturday’s defeat at West Brom proved to be the final straw for Blues owner Roman Abramovich.
A Chelsea statement read: “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 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.”