Jose Mourinho's three-year reign at Chelsea came to an abrupt end on Thursday as the Portuguese manager's fraught relationship with the club's Russian owner, Roman Abramovich, finally reached breaking point.
An announcement that will send shockwaves through English and European football came in the early hours of Thursday morning with Chelsea claiming that Mourinho had left "by mutual consent."
A terse statement posted on the London club's website stated: "Chelsea Football Club and Jose Mourinho have agreed to part company today (Thursday) by mutual consent."
Mourinho had reportedly informed Frank Lampard and other senior players that he was on his way out on Wednesday evening and late-night talks at Stamford Bridge concluded with confirmation of his departure.
The Portuguese manager, who made his reputation by guiding FC Porto to UEFA Champions League glory in 2004, has transformed the English football landscape since taking over at Stamford Bridge in June 2004, winning two Premier League titles in his first two years in charge, the FA Cup last season and the League Cup in 2005 and 2007.
Of the 185 games he has been in charge, Chelsea have won 124, drawn 40 and lost 21, a record that includes a 60-match unbeaten run in Premier League matches at Stamford Bridge.
The statistics go some way towards justifying Mourinho's famous description of himself as "a special one."
That comment was made in his first press conference in England and it is a judgement that few Chelsea fans would dispute after three years which saw the club end its 50-year wait to be crowned champions and establish itself as one of the most feared teams in Europe.
However, the success has failed to seduce Abramovich and the Russian's relationship with his most outspoken employee turned sour last season when he refused to come up with the funds Mourinho required to land his January transfer targets, a stance the Portuguese believes contributed to Chelsea conceding the Premier League title to Manchester United.
On the other side of the feud, Abramovich has grown increasingly impatient with the fact that, after investing nearly 500 million pounds (one billion dollars) in the club, Chelsea have failed to conquer Europe and continue to lag behind the likes of Arsenal, Barcelona and Manchester United in terms of entertainment value.
Tuesday's disappointing 1-1 Champions League draw with Norwegian side Rosenberg - watched by fewer than 25,000 fans - appears to have brought simmering tensions to the boil, and with hindsight, Mourinho's pre-match comments about the need to buy the best eggs to make the best omelette offered a hint that things were not going smoothly behind the scenes.
Mourinho and Abramovich appeared to have agreed to bury their differences over the summer and the manager had started this campaign pledging that he would be a much more "chilled" figure than in his first two seasons in England.
However, the strain of Chelsea's poor recent form was evident on Saturday, when Mourinho tossed a flat-screen television set to the ground in frustration over a disallowed goal in his side's 0-0 draw with Blackburn.
The manager has also made no attempt to disguise his frustration with Chelsea's misfiring striker Andriy Shevchenko, whose £30 million signing from AC Milan is widely believed to have been ordered by Abramovich.
Mourinho has also clashed with the Russian owner over backroom appointments, notably the May 2005 recruitment of Dutchman Frank Arnesen as the club's youth/scouting supremo and the appointment of Avram Grant as director of football.
Grant is likely to be in charge of Chelsea for Sunday's trip to Manchester United but it is thought likely that Abramovich will be looking to bring in a high-profile successor to Mourinho.
Russia coach Guus Hiddink and former Germany boss Jurgen Klinsmann are likely to top the speculative short-list, which may also include Sevilla's highly-rated Juande Ramos.