Birmingham City boss Pep Clotet has left the club after Wednesday's 3-1 defeat by Swansea City.
The Spaniard, 43, was set to leave the Championship side at the end of the season but said it was "mutually agreed" he would step down immediately.
Birmingham have not won in 10 league matches and are 17th in the table.
Clotet was assistant to former boss Garry Monk before succeeding him as head coach, initially on an interim basis, in June 2019.
He had previously worked under Monk at Swansea and Leeds, before a brief spell as Oxford manager, but when Monk was sacked by Blues last summer, they parted on bad terms.
Before his new club Sheffield Wednesday played Birmingham in November, Monk said he had made an "error of judgement" in working with Clotet.
But the pair shook hands before a February meeting between the two clubs at St Andrew's in February.
Birmingham were deducted nine points in the 2018-19 season for breaching the English Football League's profitability and sustainability rules.
And they spent part of this season under another EFL investigation into a financial misconduct charge, but that was dismissed in March, only for the independent disciplinary commission's decision to be overturned on appeal last month.
Despite the appeal decision, the club were not docked any points on this occasion.
Birmingham have picked up just two points out of a possible 15 since the Championship restarted after lockdown and are now just four points above the relegation zone.
Their next match is away to fellow strugglers Stoke on Sunday.