Callum Davidson has lost his job as St Johnstone manager after the Perth side were dragged into another relegation battle.
The club announced that it had been “mutually agreed that a change is required” following talks between chairman Steve Brown and Davidson.
Saturday’s 2-0 defeat at Livingston meant Saints had only collected two points from their last six cinch Premiership games to leave them five off the bottom and four clear of the play-off spot.
Brown said on the club’s website: “First and foremost, Callum is a friend and I hold him in high regard which is why this has been an extremely difficult decision to come to.
“But we had an open and honest conversation and we both agreed that we must do what is right for St Johnstone.”
Davidson led Saints to a double cup triumph in 2021 in his first season in charge, tripling the club’s major trophy count.
But they only avoided relegation through the play-offs last season and a top-six push fell away this term.
Brown added: “We must always put our football club first.
“Callum has been a brilliant manager for St Johnstone and led us to that cup double in 2021 and then European football.
“But we feel results haven’t been good enough in recent weeks and it’s best for the football club to make a change at this stage.
“I’d like to thank Callum for his service and dedication to us and wish him every success in the future.
“He is a St Johnstone legend and always will be.”
Former Scotland left-back Davidson began and ended his playing career with the Perth club.
He said after Saturday’s defeat in West Lothian: “I can understand the fans’ frustration because I’m probably even more annoyed watching that than they are.
“This is a tough league but I just expect my players to be better than they were today.
“Our results haven’t been great in the last three or four games and we should be doing better.”
Saints announced that assistant manager Steven MacLean would take interim charge “until further notice”.
They host Hibernian next Saturday before the Premiership splits in two for the final five games of the season.