Northampton suffered a second straight Champions Cup defeat as they were beaten 24-7 by Clermont Auvergne in an ill-tempered affair at the Stade Marcel Michelin.
The English side were hammered 57-13 by Saracens in round one and, despite a committed display in France, they could not compete with Clermont.
Last season's Champions Cup finalists scored four tries, with No. 8 Fritz Lee, replacement Charlie Cassang (two) and prop Etienne Falgoux all touching down as they eased home despite the early loss of fly-half Camille Lopez with a serious leg injury.
The horrific nature of the blow shocked the home crowd, and France international Lopez looks set for a long spell on the sidelines.
Cassang was introduced in his place, and the hosts began the game in typically powerful fashion with Lee smashing his way over from close range off the back of a strong scrum. Morgan Parra converted.
Saints went close when Harry Mallinder and Ben Foden combined, only for the wing to be brought down just short of the line, and the visitors then had a try disallowed when Courtney Lawes fought through a Clermont maul.
Northampton's task became a lot more difficult when hooker Dylan Hartley was sent to the sin-bin for charging into a ruck and making contact with Clermont tighthead Rabah Slimani.
Hartley's 10 minutes on the sidelines was to prove costly as his replacement Mikey Haywood then left the field with a blood injury. Down to 13, Saints soon fell further behind as Cassang raced through a gap for Clermont's second try. Parra added the extras for a 14-0 home lead at the break.
Cassang made it two for the afternoon straight after the game resumed, gathering a cross-kick from Parra. The France international failed to add the extras.
Saints did not throw in the towel, however, and forced themselves back into the game when Christian Day scored courtesy of a powerful driving line-out. Mallinder converted
Northampton were given a lifeline when Slimani was given a yellow card after running into a ruck and deliberately hitting Hartley.
But replacement prop Falgoux grabbed the bonus point for the hosts after France centre Remi Lamerat cut through Saints' defence. He offloaded to Lee, who shifted the ball on to the 20-stone prop for the game's final try.
The result left Northampton up against it in their bid to qualify for the Champions Cup quarter-finals while Clermont - who were beaten in last season's final by Saracens - are sitting pretty with two victories.
