Chelsea have appointed former Liverpool boss Rafael Benitez as interim manager until the end of the season.
He replaces Roberto Di Matteo, who was sacked on Wednesday following a 3-0 Champions League defeat by Juventus.
Benitez, 52, becomes Chelsea's ninth manager since Roman Abramovich became owner in 2003.
But his short-term appointment could pave the way for Abramovich to make a summer approach for ex-Barcelona coach Pep Guardiola.
A Chelsea statement said: "The owner and the board believe that in Benitez we have a manager with significant experience at the highest level of football, who can come in and immediately help deliver our objectives.
"The two-time Uefa Manager of the Year comes with outstanding pedigree."
Benitez joined Liverpool from Valencia in 2004 and won the Champions League in 2005, as well as reaching the final in 2007, before leaving Anfield by mutual consent in 2010.
He has been out of work since he was sacked by Inter Milan in December 2010. He spent just six months in charge of the Serie A club despite winning two titles - the Club World Cup and Italian Super Cup.
The Spaniard is due to meet the Chelsea players at the club's training ground in Cobham on Thursday. His first match in charge is Sunday's visit of Premier League leaders and reigning champions Manchester City.
Before his appointment was confirmed, Benitez admitted his interest in the job to Abu Dhabi-based website Sport 360.
"I am looking for a club that can challenge for trophies and Chelsea is one of these clubs," he said.
When he was asked about the prospect of managing on a short-term basis, he added: "I am just trying to go to a team that can win. So we will find ways to have a challenge like this."
Former Chelsea midfielder Nigel Spackman suggested Benitez's appointment would be unpopular with Blues fans.
He told BBC Radio 5 live: "You won't find many Chelsea fans happy with an appointment of an ex-Liverpool manager.
"Benitez has got a great CV and a good record, but the only way he will win the Stamford Bridge crowd over is getting the results. Now he had to focus on trying to win the Premier League.
"He is the interim manager but if he does a good job maybe he will get it for longer."
David Johnstone, spokesman for Chelsea fanzine cfcuk, told BBC Sport that fans would be unhappy with Benitez as their new boss.
"Rafa Benitez is not a Chelsea manager," he said. "Some people are born to play for or manage certain clubs and for us, Benitez isn't what we want.
"When he was Liverpool manager and Jose Mourinho was Chelsea boss there was a bit of 'beef' between them.
"He was very dismissive of Chelsea, very rude towards us, and my impression of him was that whenever anything went wrong it was always somebody else's fault, not his."
Former Liverpool and Germany midfielder Dietmar Hamann, a Champions League winner under Benitez at Anfield, believes the Spaniard will improve Chelsea.
"He is a very talented and outstanding manager," he said. "He's a very meticulous worker and he puts a lot of emphasis on tactical exercises."
Chelsea's declaration that Benitez is only manager until the end fo the season indicates Abramovich is still interested in landing Guardiola once the former Barcelona manager decides to return to the game.
Guardiola, 41, is midway through a 12-month sabbatical after leaving Barcelona at the end of last season. He won 14 trophies in four years at Barca, including three titles and the Champions League twice.
Di Matteo, 42, won the Champions League and FA Cup as caretaker manager last season and was given a two-year deal in June.
The Italian spoke of his "deep and unreserved passion" for Chelsea despite being sacked as manager after just eight months in charge.
His dismissal came hours after defeat to Juventus, leaving the Blues on the brink of a Champions League exit.