A fortuitous last-minute try from Tom Casson gave defending Aviva Premiership champions Harlequins a remarkable 31-28 victory over London Irish at the Madejski Stadium.
Casson thought he had blown the opportunity in the last play of the game but the television match official ruled that what appeared to be a knock-on had in fact come off Casson's knee, making his subsequent grounding a legal one.
The defeat was harsh on the Exiles who matched Quins throughout and looked destined to claim a vital win behind Ian Humphreys' outstanding kicking display which returned 23 points.
Tries from Danny Care and Tom Williams put Quins clear at 26-19 with just over 20 minutes remaining but back came the Exiles behind Humphreys' boot before Casson's late effort.
Guy Armitage scored the Exiles' only try while Ben Botica completed the scoring for Quins with 16 points from the boot.