Northampton Saints failed in their bid for back-to-back wins in the Heineken Cup as they slipped to defeat away to Perpignan.

Chris Ashton and Brian Mujati scored either side of half-time as Saints desperately tried to stay in touch with the French champions.

But Perpignan did not relinquish their lead from the seventh minute as they atoned for their shock loss to Benetton Treviso a week earlier in style.

The Perpignan scrum earned a penalty try and David Marty also scored as the hosts led 20-8 at half-time before Jerome Porical completed a 19-point haul in the second half to deny Northampton a losing bonus point.

For Northampton, the game was in stark contrast to their opener, when they lowered the colours of two-time European champions Munster.

However, Perpignan had lost just twice in 28 Heineken Cup games at Stade Aime Giral and were hurting following their 9-8 defeat at Treviso, and they made a lively start as they looked to get their European campaign back on track.

Northampton's Lee Dixon saw his kick charged down and Dylan Hartley threw an unnecessary pass that eventually allowed Porical the first score with a penalty.

More points could have followed but Jean-Pierre Perez dropped a pass with the try line at his mercy while Neil Best managed to hold up Julien Laharrague over the line.

However, Perpignan had a clear edge in the scrum and after Saints prop Santiago Bonorino was warned for collapsing the scrum for a third time, Welsh referee Nigel Owens awarded a penalty try after 15 minutes at the fourth time of asking.

Porical converted and then exchanged penalties with Shane Geraghty before Ashton went over after 26 minutes, winning the race for his own kick as the bounce evaded two defenders.

Geraghty missed the conversion though and Perpignan struck for a second time just before half-time.

Laharrague's kick split Northampton's defence, and was collected and shipped on in one move by Maxime Mermoz to leave Marty with a straight sprint for the line from 40 metres to open a convincing lead at half-time.

Henry Tuilagi thought he had extended the lead but his try was ruled out for a forward pass from Perez and Northampton were forced into a desperate defensive stand on their own try line.

However, Ashton and Jon Clarke combined with Bruce Reihana to launch a stunning counter-attack that ended with Soane Tongauiha's scoring pass to replacement prop Mujati.

Geraghty was again off-target and despite Best and Phil Dowson going close, it was the right boot of Porical that produced the only further points, kicking three more penalties to complete a comfortable win for Perpignan.