Chelsea appointed Rafael Benitez as their interim first team-manager until the end of the season on Wednesday after the European champions sacked Roberto di Matteo.
Di Matteo was fired after Tuesday's 3-0 defeat by Juventus in Turin left Chelsea facing elimination at the group stage of the Champions League.
Roman Abramovich, Chelsea's Russian billionaire owner who has now sacked seven managers since buying the club in 2003, subsequently appointed former Liverpool boss Benitez, albeit in a caretaker capacity.
"Chelsea Football Club can confirm Rafael Benitez has been appointed interim first-team manager until the end of the season," said a club statement.
"The owner (Abramovich) 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."
Hours later former Blues midfielder di Matteo who, after replacing the sacked Andre Villas-Boas in March, led Chelsea to an FA Cup and Champions League double, with the Blues beating Bayern Munich on penalties in May, gave his first public reaction in a statement issued by the League Managers' Association.
"It was an honour for me to be appointed manager of a club that I loved playing for and one that is so close to my heart," said di Matteo.
"I am extremely proud of the successes and trophies that we were able to bring to the club in recent months.
"Lifting Chelsea's first Champions League trophy, in Munich, was the best achievement in club history and without doubt the highlight of my career to date, both as a player and manager," said the former Italy midfielder, who played in two FA Cup winning teams.
"It is a memory I will treasure for the rest of my life.
"I have a deep and unreserved passion for Chelsea Football Club and I would like to sincerely thank all of the staff, my players and of course the Chelsea fans, for their tremendous and unconditioned support in the intense time I have been the manager at the Bridge.
"I wish all of them every success for the rest of the season and beyond," added di Matteo, only appointed on a permanent basis in June.
Chelsea's statement said Benitez came with an "outstanding pedigree".
But the fact the 52-year-old Spaniard joined Chelsea on a short contract is bound to intensify speculation that former Barcelona boss Pep Guardiola, currently on a one-year sabbatical from football, is the man Abramovich truly wants to take charge at Stamford Bridge on a full-time basis.
At Valencia, Benitez twice won the Spanish League and the UEFA Cup while his six years at Liverpool yielded an FA Cup and the club's fifth European Cup.
Benitez left Liverpool by "mutual consent" in 2010 after the club finished the Premier League season in seventh place, their worst position since 1999.
However, days later, he then took charge of Inter Milan only to quit months later in December 2010 over the Italian giants' alleged failure to back him in the upcoming transfer window.
Earlier on Wednesday, Chelsea explained fans' favourite di Matteo's dismissal by saying "recent performances and results have not been good enough".
Chelsea made a superb start to the current season, winning seven and drawing one of their opening eight league games to move four points clear at the Premier League summit.
But a 3-2 loss at home to Manchester United last month marked the start of a run of four games without a win.
Saturday's 2-1 defeat at West Bromwich Albion, di Matteo's former club, left Chelsea four points behind leaders Manchester City in third place.
Chelsea spent over £80 million ($127 million, 100 million euros) on new players in the close season, notably bringing in Belgian winger Eden Hazard from Lille and Brazilian attacking midfielder Oscar from Internacional.
Although the quality of their football drew praise from pundits in the season's early months, that initial momentum appears to have disappeared.