Sligo Rovers 2 Shamrock Rovers 0
Goals from Gavin Peers and Eoin Doyle finally gave Sligo some joy against their rivals from Dublin.
Paul Cook's Bit O'Red had lost their other four games to Shamrock Rovers this season.
But with the Hoops still reeling from their poor display when having to come from 2-0 down to salvage a draw with Dundalk on Tuesday, Sligo produced a terrific display to delight their fans.
Central defender Peers headed home man-of-the-match Joseph Ndo's corner for the lead goal on 38 minutes.
Topscorer Doyle added the second in the first minute of stoppage time when latching onto John Dillon's pass to take the ball around Alan Mannus and shoot to the net.
Sligo's win knocks Shamrock Rovers off the top of the table, to bring themselves right into the picture and blow the title race wide open.