Prem leaders Northampton were handed a European lesson by Champions Cup holders Bordeaux in a repeat of last year’s final.
Saints lost 28-20 in May’s tight and ill-tempered Cardiff showpiece but were blown away this time by a brilliant eight-try performance from the hosts in an electric atmosphere.
Star Saints back row Henry Pollock was booed throughout by a passionate home support after his part in a final-whistle scuffle in Cardiff.
The flamboyant flanker had his moments, scoring twice, but it was Bordeaux who surged on to ruthlessly exploit a gulf in class.
The French side were quicker, stronger and far more creative as they put on a clinical display, with Fiji full-back Salesi Rayasi and forward Cameron Woki both scoring hat-tricks.
Saints lost influential fly-half Fin Smith before kick-off but the England man would surely have made little difference against a Bordeaux side who have now won 24 of their past 27 home games.
Rayasi touched down the opener before Pollock’s inevitable moment of theatre. The England forward found himself on the left wing, kicked it ahead and gathered to run in and score before shushing the booing from the stands.
Saints then struggled at the scrum, with prop Danilo Fischetti being sin-binned, and they fell behind when a man down as Rayasi swapped passes with Damian Penaud to score.
Northampton went down to 13 men when flying winger Louis Bielle-Biarrey was taken out late by Rory Hutchinson and were still a man short when scrum-half Martin Page-Relo sniped through a gap in the stretched defence to score a sparkling third.
Penaud put Woki in to score a bonus point before the break and Rayasi completed a world-class hat-trick early in the second half with a ridiculous run from his own half, weaving and leaving Saints defenders in his wake.
Woki intercepted a pass to run in and score a second, before Tommy Freeman cut the lead with a fine finish after some concerted pressure.
Bordeaux again scored with ease though, Woki pocketing the loose ball from the restart to run in for his third before fly-half Matthieu Jalibert sprinted clear to bring up the 50 points on the hour mark.
Saints kept going, as Pollock scored a second fine try from a kick from Hutchinson in the closing stages and Fischetti stretched out to secure a potentially vital bonus point.
Northampton are through to the last 16 already but may now face another testing trip away from home.