Tom Wood jokingly thanked Clermont for inviting Northampton to an open training session after the English champions were thrashed 37-5 in the Champions Cup. The Saints, who sit 10 points clear at the summit of the Aviva Premiership, exited Europe at the quarter-final stage after being routed four tries to one at the Stade Marcel-Michelin. The result had been decided by half-time as Clermont, employing a mixture of forward supremacy and three-quarter devilry, amassed an unassailable 27-0 lead. Calum Clark and Tom Wood walk off the pitch after their 37-5 defeat against Clermont . Northampton captain Dylan Hartley leads his team off the pitch after crushing defeat . Clermont winger Napolioni Nalaga runs with the ball during the match against Northampton . And Wood tweeted: 'Thanks to Clermont for inviting us to their open training session today. We've left our non-contact bibs in the changing rooms #humbled.' Northampton director of rugby Jim Mallinder, meanwhile, admitted defeat was among the most distressing nights of his career. 'It's one of the worst defeats I've experienced. We've had a few shockers and that's definitely one of them,' he said. Nick Abendanon of Clermont dives over to score a try at the Stade Marcel-Michelin . Abendanon cast his magic over the saints defence to inspire comprehensive victory . Clermont's  Wesley Fofana runs with the ball during the European Rugby Champions Cup match . 'We're disappointed because clearly we wanted to progress and have the chance of a home semi-final. We have to take this on the chin. 'We were well beaten. We came up against a very, very good side. Clermont played very well and we didn't. When you're losing 27-0 at half-time, that's basically game over. 'You come into these games knowing you have a chance, but that you'll have to play to your very best. Clermont winger Noa Nakaitaci (right) scores his second try against Northampton . Fofana is tackled during the European Rugby Champions Cup  match between Clermont and Northampton . Lee Dickson  kicks the ball out of a scrum during the match between Clermont and Northampton . 'We didn't do that and so were well beaten. Now our focus has to be on retaining the Premiership, it's as simple as that.' Wing Noa Nakaitaci claimed two tries and his France team-mate Wesley Fofana and former Bath full-back Nick Abendanon also crossed as England's strongest club was put to the sword. It took until the 68th minute for Northampton to register their first and only points through a try by Alex Waller. Nalaga runs with the ball during the European Rugby Champions Cup match  at the Michelin stadium . 'We talked about needing to make a good start and shutting the crowd up, but completely the opposite happened,' Mallinder said. 'Clermont made a cracking start, put us under pressure and we clearly didn't compete in the first half in any of the areas. 'The set piece didn't function. The physicality wasn't there. We couldn't keep hold of the ball, spilling it too often. Our kicking and kick chase were also poor.' Clermont and Northampton players vie in a scrum during the match  at the Michelin stadium . Northampton's Ken Pisi is tackled by Clermont's French centre Wesley Fofana . Northampton's status as Premiership champions points to a gulf in class between the English and French leagues that Mallinder was in no hurry to deny. 'The top French teams are very, very good. And at times we are very good, but not in this match,' Mallinder said. 'On this performance it would be hard to argue against it (there being a gulf in class), but we have competed against their top sides in the past.' Lock Courtney Lawes and prop Alex Corbisiero suffered respective shoulder and leg injuries, but Mallinder was unable to elaborate on the severity of their injuries.
Tom Wood took to Twitter to jokingly thank Clermont for training session .
Tweet came after Northampton were thrashed 37-5 in the Champions Cup .
Hosts amassed an unassailable 27-0 lead by half-time in France .
Northampton director of rugby Jim Mallinder admitted defeat was among the most distressing nights of his career .