Top 14 sides Clermont Auvergne and La Rochelle got the better of Premiership rivals Bristol Bears and Northampton Saints to move into the last four of the European Challenge Cup on Sunday.
High-flying Clermont produced a stunning late show as they had too much for Northampton, accelerating out of sight to run out 61-38 winners.
The scoreline was just 22-3 at half-time but each side produced remarkable rallies that contributed to an incredible final scoreline.
Luther Burrell, Alex Mitchell and Rory Hutchinson scored in the space of four minutes for Saints to move within six points of the French side, but then Clermont obliterated their opponents.
They provided three tries in five minutes and both Damian Penaud and Peter Betham completed hat-tricks in a barnstorming finish.
However, one of the pivotal moments was when Taqele Naiyaravoro sparked a melee, earned 10 minutes in the sin-bin and conceded a penalty try after barging Arthur Iturria into touch with a no-arms tackle.