Tony Pulis has been sacked by West Bromwich Albion.
Owner Guochuan Lai made the decision after witnessing West Brom lose 4-0 at home to Chelsea.
The febrile atmosphere among supporters, who chanted repeatedly for Pulis to go, was a contributing factor.
Sportsmail understands Pulis was given the news by chairman John Williams on the phone on Monday morning and West Brom will now begin the search for a successor.
Lai and Williams acted due to a run of two wins from 21 Premier League games that has plunged West Brom into relegation dangers. The club are only one place and one point above the drop zone.
Williams said: 'These decisions are never taken lightly but always in the interests of the club.
'We are in a results business and over the back end of last season and this season to date, ours have been very disappointing.
'We would like to place on record our appreciation of Tony's contribution and hard work during a period of transition for the club which included a change of ownership. We wish him well in his future endeavours.'
Pulis appeared to accept his fate during post-match media briefings on Saturday.
The 59-year-old, who had dinner with Lai on Friday night, had said: 'The big thing is this is not about me, it's not about the chairman, the owners or anything else. It's about the football club and what is the right decision for the football club.'
Asked if the right decision would be for him to be relieved of his duties, Pulis said: 'I've been in the game long enough to know if you get bad runs that's what happens.'
West Brom have dismissed suggestions talks have taken place with Michael O'Neill but it is clear an fresh injection of ideas is required in the dugout.
Pulis's assistant Gary Megson will take charge of first-team affairs in the interim period, with his first match against title-chasing Tottenham on Saturday.
Megson is a popular figure at the Hawthorns having led the club to two promotions from the Championship and was brought back by Pulis this summer to replace departing No 2 Dave Kemp.
While no successor has been lined up by West Brom, the club are seeking a swift appointment and high among the list of candidate requirements is Premier league experience.
That would again bring Sam Allardyce into the reckoning, with Alan Pardew's name also being mentioned at the Hawthorns.
PULIS' WEST BROM REIGN IN NUMBERS
37 - West Brom's average possession this season is the lowest in the Premier League.
22 - The Baggies had just 22 per cent of the ball in last month's 3-2 home loss to Manchester City.
1 - West Brom have had more possession than their opponent only once this term, at Brighton in a 3-1 defeat in September.
109 - goals scored by Pulis' side in 106 matches.
6 - number of clean sheets West Brom have kept this calendar year.
11 - games since West Brom last won.
2 - number of victories the Baggies have recorded in their last 21 Premier League fixtures, both of which came in August.
4 - the run of league defeats that signalled the end of Pulis' reign.