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.
English clubs Sale Sharks and Harlequins had booked their places in the semi-finals earlier in the weekend, but French clubs retained their interest in the competition with a pair of strong showings.
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.
La Rochelle comfortably dispatched of Bristol in the day's early match, winning 39-15 on home soil.
The Bears were never really in the contest after Gregory Alldritt crossed for the hosts' opening try, with the lead stretched further by a penalty try and Geoffrey Doumayrou's effort.
Steven Luatua closed the gap late in the first half but Bristol could not hold on to half-time, conceding again to Wiaan Liebenberg.
Vincent Rattez - influential in the opening period - scored the first try of a quieter second half with nine minutes remaining, before Piers O'Conor was allowed through for a consolation.