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."
- Football365.com
should have sacked him after boro was relegated at end of season.
Former Celtic boss Gordon Strachan was appointed manager of Championship team Middlesbrough on Monday.
"It's a special job," Strachan told Middlesbrough's website after replacing Gareth Southgate who was sacked last week.
"I don't have to be here, I don't need to be here, I want to be here. I don't need football but when I'm in it, I love it," added the 52-year-old after signing a four-year contract with the English team.
Former Scotland and Manchester United midfielder Strachan left Celtic in May after spending four years at the Glasgow club.
Middlesbrough, relegated from the Premier League in May, are fourth in the Championship after drawing 2-2 at Preston North End on Saturday.
Strachan has also managed Coventry City and Southampton, the team he took to the 2003 FA Cup final where they lost 1-0 to Arsenal.
he will leave after brough dont promote.