Andrew Shinnie found the back of the net late in the game to secure a victory for Livingston over Ross County in the Scottish Gas Scottish Cup.
His goal in the 119th minute caused a major upset, marking the first surprise result of the fourth round.
Ross County has not won a match in the competition for six years, with their most recent victory dating back to January 2019 when they defeated Motherwell 2-1.
Facing off against a Livingston side aiming to return to the top flight after being relegated last season, Ross County made just one change from their previous match, bringing in striker Jordan White for Connor Randall. The newcomers Ashworth and Tomkinson were named as substitutes.
Livingston, currently in third place in the Championship, four points behind leaders Falkirk, started the game on the front foot as James Brown almost opened the scoring with a well-struck shot from the right wing which forced a save from goalkeeper Jerome Prior.
Responding to the early pressure, Livingston came close to breaking the deadlock when Stevie May's shot from distance was parried away for a corner by Jordan Amissah.
The visitors eventually took the lead just before half-time in a peculiar manner, as a penalty was awarded to Livingston after Akil Wright handled Scott McAlear's free-kick in the box. Robbie Muirhead duly converted the spot-kick to give Livingston the advantage.
Ross County equalized in the second half through Jordan White, but Livingston regained the lead with Cristian Montano's strike following a defensive lapse from the Staggies.
Although County managed to level the score once again through Ronan Hale, Livingston had the last say as Andrew Shinnie secured the win with a late goal in extra time, firing home a cross from the right wing.