Luton Town have sacked manager John Still after four straight defeats, with the club 17th in League Two.
The 65-year-old took charge in February 2013 with the Hatters in the Conference Premier and led them to promotion back to the Football League a year later.
Academy and development boss Andy Awford has been placed in charge until further notice.
"The decision was a unanimous one by the board," said Luton chief executive Gary Sweet.
"We are genuinely saddened that our partnership with John has come to an end earlier than we expected.
"We had hoped John would be with us for the longer-term but now attention turns to finding the next man for the job."
After promotion in 2013-14, Still led the club to an eighth-place finish last season, just one place outside the play-offs, having dropped off the automatic promotion pace.
The former Peterborough and Dagenham boss told BBC Three Counties Radio on earlier this month that he felt "no pressure", citing the transformation in the club from a non-league outfit when he took charge.
Still said in a statement: "Naturally I am hugely disappointed to be leaving Kenilworth Road but I would like to thank everyone involved at Luton Town for making my time at the club an enjoyable one.
"The board of directors have been fantastic every step of the way, all of the staff - on the football side and behind the scenes - have been unbelievably supportive and the fans have been nothing short of incredible.
"The Conference championship season is one which will live long in my memory and I was proud and honoured to have played a part in bringing Luton Town back in to the Football League."
Analysis: BBC 3CR's Geoff Doyle
"I'd hope the majority of players at Luton Town are taking a long, hard look at themselves today and questioning whether there was more they could have done to keep John Still in his job.
"The players simply haven't performed to their abilities this season. Could Still have done more to address that? Probably. He may have been too lenient with them and in tough times stuck to his usual principles on the training ground which may be a bit out-dated these days.
"His recruitment must be analysed too; this is currently a team of individuals lacking leadership and togetherness on the pitch. Still's reign ended in boos but he'll be forever remembered as the Hatters boss who returned Luton to the Football League."