Donegal Celtic have been plunged back into the automatic relegation picture in the Premiership after effectively being hit by a six-point swing following an Irish FA investigation.
The Irish FA found that Sean Cleary played while under suspension during the recent 2-1 win over their fellow strugglers Lisburn Distillery.
DC have been docked three points with Distillery instead awarded a 3-0 win.
This leaves DC only two points ahead of Distillery who have a game in hand.
Prior to the IFA ruling, the west Belfast club were in a position of relative safety in terms of the automatic relegation spot as they were eight points ahead of the Whites.
In addition to the points deductions, Donegal Celtic have also been fined £500.
Cleary scored what turned out to be the winning goal in the bottom-two clash at Suffolk Road.
The ex-Cliftonville player got a one-match ban for picking up five yellow cards this season but then received a further one-game suspension for a red card at Ballymena.
The Irish FA disciplinary committee ruled that Cleary should have missed two matches - the Premiership game away to Cliftonville and the relegation clash against Lisburn Distillery.
He did sit out the 2-1 defeat at Cliftonville but played and scored in the crucial win over the Whites.
Donegal Celtic maintain that the Irish FA did give Cleary the all-clear to play in the game against Distillery.
"We made the call to the IFA for clarification and the association came back with the wrong answer," said a clearly unhappy DC manager Pat McAllister on Monday night.
The bottom club in the Premiership will be automatically relegated to the Championship with the second-bottom outfit involved in a relegation play-off against the Championship runners-up.
Meanwhile, Irish League managing director Colin Marks has stepped down after only a few months in the role for personal reasons.