A late Dan Evans try sealed a dramatic win for the Ospreys in Bridgend as Connacht fell to a 22-17 loss at Brewery Field.
The hosts raced out to a 10-0 lead thanks to a quickfire double from winger Keelan Giles before Jack Carty cut the gap to seven with a drop goal three minutes later.
The Ospreys brought that advantage into half-time before Harri Morgan made it a two-try game with another score after the restart.
Ireland centre Bundee Aki gave the visitors some hope when he crashed over from close range after latching onto a Connacht maul just in front of the Ospreys line before Jarrad Butler tied it all up at 17-17 with a score of his own 10 minutes from time.
Both sides looked headed for a draw before centre Cory Allen cut through the Connacht defence only to be hauled in metres from the line.
Connacht substitute Kyle Godwin managed to knock the ball loose from Allen only for Evans to pick up possession and cross the line for the match winner after referee Mike Adamson consulted with TMO Neil Paterson before awarding the try.
Briseadh croí do Connachta.
Drama from the #GuinnessPRO14
Last minute try gives Ospreys a huge win over Connacht. @ospreys 22-17 @connachtrugby pic.twitter.com/PXjNIixO8S— Spórt TG4 (@SportTG4) October 26, 2018
A sickening way to lose for Connacht who were looking to bounce back after a 34-13 thumping at the hands of Sale in the Challenge Cup last weekend.