LONDON—Andre Villas-Boas was fired by Chelsea after barely eight months in charge of the Premier League club on Sunday, leaving owner Roman Abramovich searching for his eighth manager in nine years.

The Russian oligarch lost patience with the inexperienced 34-year-old after Chelsea's first loss to West Bromwich Albion since 1979 on Saturday left the club fifth in the league, in danger of missing out on a lucrative Champions League qualification place.

"Andre Villas-Boas has parted company with Chelsea," the club said in a statement. "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."

Assistant coach Roberto Di Matteo, a former Chelsea player and West Bromwich Albion manager, will take charge of the Blues until the end of the season. His first game in charge will be Tuesday's FA Cup fifth-round replay at Birmingham.

"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," Chelsea said. "With that in mind, we felt our only option was to make a change at this time."

Villas-Boas has been under constant pressure since being hired in June on a three-year contract to replace Carlo Ancelotti, who was fired after failing to win a trophy last season despite a league and FA Cup double the previous year.

That change of managers cost Chelsea $45 million in compensation. Villas-Boas is likely to receive compensation after being fired with more than two years remaining on a contract reportedly worth $8 million annually.

Having repeatedly insisted he had the owner's full backing, Villas-Boas appeared to acknowledge his job was under threat after the 1-0 loss to West Brom left Chelsea with three wins in the last 12 league matches.

Villas-Boas had two seasons of topflight managerial experience behind him when he was hired by Chelsea last June on a three-year deal.

Winning four trophies with Porto last season had established him as one of Europe's most highly rated coaches. He was dubbed by many as the "Mini-Mourinho," after the current Real Madrid coach who has been one of the most successful managers in Europe in recent years.

Villas-Boas was a scout at Chelsea between 2004-07 under Mourinho, who won five major domestic trophies in that time.

However, Mourinho and successors Avram Grant, Luiz Felipe Scolari, Guus Hiddink and Carlo Ancelotti always came up short in the Champions League.

Since Abramovich bought Chelsea in 2003, the club has won three English titles, three FA Cups and two League Cups.

But the Champions League is the competition Abramovich is said to be obsessed with and the Blues face another season of failure unless they can overcome their 3-1 loss at Napoli in the first leg.

On Friday, Villas-Boas insisted he would "never" quit Chelsea.

"Am I the right man for the job? Yes," he said. "I wouldn't have taken it if I didn't think that."