Glentoran manager Paul Millar has been sacked after only 16 months in the job.
Paul Millar's Glentoran side led the league table at Christmas
A statement on Glentoran's website said that Millar's contract had been "terminated with immediate effect".
Glentoran led the Carnegie Irish League table at Christmas but they had a poor second half to the season - although they did claim the runners-up spot.
They were beaten in the sixth round of the JJB Sports Irish Cup by Portadown and lost the County Antrim Shield semi-final against Cliftonville.
Prior to Christmas, the Glens had won the CIS Cup.
On Wednesday, Millar told the BBC that he intended to stay in the role and pointed out that his team had secured a place in the Uefa Cup.
However, clearly this was not enough to keep the former Newry manager in the Oval post.
Glentoran chairman Stafford Reynolds hinted that the board's decision to dispense with Millar's services had not been unanimous.
"It was the decision of the majority of the board members and we had to abide by that," Reynolds told BBC Sport.
The Glentoran chairman added that there had been "quite a few successes" during Millar's spell in charge.
"There was no lack of effort and ambition and enthusiasm from Paul.
"But like most things, success is a fickle area. It can change very, very quickly and it can be determined by the bounce of the ball."
Millar's assistant Alan McDonald, who was appointed as assistant boss in February, is likely to be linked with the vacancy.