Shamrock Rovers clinched the Airtricity League Premier League title after Dean Kelly's injury-time goal earned a 2-1 win over UCD on Tuesday night.
The title race between holders Rovers and Sligo looked set to go down to Friday's final series of games as the match entered injury-time at Belfield.
However, Kelly hit the winner three minutes into injury-time.
Ken Oman put Rovers ahead on 68 before Robbie Benson levelled for the Students who had Darren Mennan sent off on 80.
Rovers lead Sligo by four points going into Friday's matches and cannot be caught.
Sligo are three points ahead of Derry City and also have a superior goal difference of 12 ahead of the Candystripes.
Shamrock Rovers are at home to Galway United on Friday with Derry hosting Bohemians and Sligo taking on UCD.