Kilmarnock suffered a shock 2-0 defeat to Connah's Quay Nomads at Rugby Park in the Europa Leaque qualifying first round on Thursday night.
The Welsh minnows overturned a 2-1 first-leg deficit through second-half goals from Ryan Wignall and Callum Morris.
Stuart Findlay was sent off for Kilmarnock after he gave away the penalty for Morris' goal, while Wignall also received a red card for the visitors late on but they held on for a famous victory.
Meanwhile, Aberdeen progressed to the second qualifying round after Lewis Ferguson's injury-time strike gave them a 2-1 win against RoPS Rovaniemi in Finland.
The Dons got off to a disastrous start in Derek McInnes' 300th game as manager when Tarik Kada put the hosts ahead after just two minutes.
Sam Cosgrove equalised from the penalty spot before Ferguson tapped the ball in from close range to give Aberdeen a 4-2 aggregate victory.
Two goals from Paul Heatley and another from Jordan Forsyth saw Crusaders win 3-2 at B36 Torshavn and go through 5-2 on aggregate, while Shamrock Rovers also progressed 4-3 on aggregate after late goals from Jack Byrne and Gary O'Neil.
St Patrick's Athletic are out after a 2-1 defeat at IFK Norrkoping and Cliftonville's 5-1 loss at FK Haugesund ended their Europa League hopes.
Cork City were 2-1 winners at Progres Niederkorn on the night, but went out 3-2 on aggregate while Ballymena United lost 4-0 at home to Malmo, who eased through 11-0 over the two legs.