Middlesbrough boss Gareth Southgate was relieved of his duties within hours of guiding his side to victory over Derby on Tuesday night.
The 39-year-old former England defender's departure was confirmed in a brief statement issued through the club's official website, www.mfc.co.uk.
The statement read: "Middlesbrough FC have tonight announced that manager Gareth Southgate has been relieved of his position with immediate effect.
"Football consultant Alan Smith will also be leaving the club as part of the change."
Chairman Steve Gibson admitted the decision to dispense with Southgate's services had been the toughest of his reign to date.
He said: "This has been the most difficult decision I have had to make in all the time I have been in football.
"Gareth has given Middlesbrough Football Club magnificent service as a skipper and, in very difficult circumstances, as manager.
"I appointed Gareth in a situation that was greatly unfavourable to him.
"He is a good man and has all the qualities and integrity that we wanted in a manager.
"However, the time is right for change and that change has had to be made.
"Gareth will always be welcome at our football club. English football needs people of his stature and we feel certain that this experience will serve him well.
"Gareth deserves another opportunity once he has had the chance to rest and refresh himself."
Rumours had been rife for several days that Southgate's days at the Riverside could be numbered, particularly after successive home defeats by West Brom, Leicester and Watford left sections of the club's support in rebellious mood.
However, Boro stopped the rot this evening when Adam Johnson's double secured a 2-0 victory over the Rams, and that appeared to have given the manager breathing space.
Asked immediately after the game about the consequences of another defeat at the Riverside, Southgate said: "There would obviously been more speculation and we would have been probably four or five places lower, which would have made life very difficult, I am sure, for all of us.
"I have had lots of games like that since I have been manager here where you wonder about the consequences of defeat, but we were very positive in the way we approached everything.
"We thought about how we could win the game. We didn't really consider the possibility of defeat, but you know all the while a fourth home defeat on the bounce would have been very difficult for people to accept.
"None of us wanted to go through that and we didn't want to put our supporters through that more than anything.
"We want them to see us winning at home and as the season goes on, we have got to make sure we do it regularly if we want to go up."
But whatever respite there was proved short-lived as Gibson wielded the axe hours later.
Ironically, he did so with Boro sitting in fourth place in the Coca-Cola Championship table and only a point adrift of leaders West Brom.
However, tonight's game was played in front of just 17,459 spectators, less than half the Riverside's official capacity and the lowest-ever attendance for a league game at the stadium.
Gibson sprang a major surprise when he appointed his then club captain as manager in the wage of Steve McClaren's departure for the England job during the summer of 2006.
Having fought for special dispensation from the Barclays Premier League to give Southgate the job without him holding the required UEFA Pro Licence, the chairman handed him a five-year contract and charged him with the task of revitalising the squad in challenging financial conditions on Teesside.
The new manager guided his side to a 12th-place finish in his first season at the helm and 13th a year later.
But last season proved far more challenging and ultimately unsuccessful as Boro slipped out of the top flight having won just seven of their 38 league games and scored just 28 goals.
