Steven Saunders came back to haunt his old side Ross County as he gave Partick Thistle a 3-2 win in the last 16 of the Betfred Cup.
Saunders, who played for the Staggies between 2013 and 2015, notched with a header in extra-time ended the Staggies’ run in the competition.
Blair Spittal put County in front in the second half but Kenny Miller’s goal 10 minutes from time took the game into an additional period.
James Penrice and Harry Paton traded goals in the first half of extra-time before Saunders struck in the 114th minute to put Thistle through.
The Staggies made three changes from the 0-0 draw at Hearts, with Keith Watson, Joe Chalmers and Spittal coming in for Callum Morris, Iain Vigurs and Josh Mullin.
Thistle started brighter and hit the bar on 11 minutes, as Chalmers glanced Joe Cardle’s corner against the frame of his own goal.
Ross Draper had County’s first sight of goal, seeing a header cleared off the line by Shea Gordon after Sean Kelly had turned Chalmers’ corner back into the six-yard box.
Draper’s namesake Stewart, who already has five goals to his name this season, ought to have done better when Michael Gardyne played him in but the striker belted his effort well wide.
County came into the game towards the end of the half and missed two glorious chances to go in front. Spittal was played through by Billy Mckay on the counter but one-on-one with ex-Staggies stopper Scott Fox, he blazed high over the bar.
Two minutes later Marcus Fraser was able to get beyond James Penrice too easily and stood the ball up to Stewart at the back post, but he directed his header over the top.
Neither goalkeeper had really been called into action but five minutes into the second half Ross Laidlaw was required, coming out quickly to block Kenny Miller’s shot after Keith Watson had misjudged a bouncing ball.
After County had cleared the resulting corner, Alex Jones was able to find space in the box and a shot through a crowd of bodies rolled just wide of Laidlaw’s far post.
The Staggies went in front on the hour when Steven Saunders cleared a long ball straight to Spittal, who crashed it straight back past Scott Fox.
The Thistle stopper, who swapped Dingwall for Firhill in the summer four years after making the reverse move, superbly prevented a second County goal by tipping over Gardyne’s swerving effort. Liam Fontaine headed over from the resulting corner.
Miller found himself in the right place at the right time to level the scores with 10 minutes to go, slotting home at the back post from Jones’ low cross.
Partick launched a late siege on the County goal with Fontaine diverting Penrice’s goal-bound shot clear and Jones firing inches wide, as extra-time beckoned.
Penrice served up a moment of quality nine minutes into extra-time as he curled a free-kick past Laidlaw, via the inside of the post.
But the scores were level again on the stroke of half-time as Paton carried Iain Vigurs’ flick into the box and finished across Fox into the far corner.
The Staggies were finally undone with six minutes to go as Saunders rose highest to direct Penrice’s corner inside the far post, handing Thistle a last-eight spot.
