Northampton kick-started their Heineken Cup campaign with a priceless 27-16 victory over Ospreys at Franklin's Gardens that put them firmly back in the Pool One mix.
The star-studded Welsh region, though, are facing an early exit after they were unable to recover from last weekend's home defeat to Leinster.
Number eight Samu Manoa, lock Christian Day and full-back Ben Foden scored tries for the Saints, with fly-half Stephen Myler converting all three touchdowns and booting two penalties.
Wales outhalf Dan Biggar posted all the Ospreys' points from a try, conversion and three penalties, yet they now have a mountain to climb in a group that also includes reigning French champions Castres, conquerors of Northampton eight days ago.
Perpignan scored four tries on their way to a 31-14 victory at home to Edinburgh that moved them ahead of Munster at the top of Pool Six.
The Scottish side had taken a 7-3 lead at the interval through Tim Visser’s try, but it was the French team that dominated after the break.
Wandile Mjekevu touched down twice, while Joffrey Michel and Justin Puril also scored as the hosts sealed the win.
Cornell du Preez crossed the whitewash late on for Edinburgh, but all their good work in the first half was undone by a disappointing second 40.
Second half tries from Tim Swinson and Tyrone Holmes were enough to confirm Glasgow's first victory of the season.
The Warriors had to wait for their final group game last season before collecting a win but they have already got themselves off the mark just two games into this year's competition after beating Exeter 20-16.
An exchange of penalties saw the Chiefs lead 9-6 at half-time but lock Swinson’s try following a moment of brilliance from Niko Matawalu nine minutes into the second half set the hosts on target for victory.
Flanker Holmes added a second seven minutes from time before visiting number eight Dave Ewers ensured Exeter left with a losing bonus point that sees them draw level with Toulon at the top of Pool 2.
