Northampton will aim to climb off the canvas on Saturday night and revive their Heineken Cup hopes against ruthless opponents who are unbeaten this season.
A week after Ulster crushed Saints in bonus point fashion at Franklin's Gardens, Northampton head to Belfast for a return fixture that will make or break their European campaign. Northampton are already eight points behind the Pool Four leaders, and a group stage exit looms large.
"I think that it stung so much because we were at home and conceded four tries," Northampton's England international full-back Ben Foden said, reflecting on last week's loss. "The performance let us down, as individuals and as a team. There was no finger-pointing. We sat down and took the blame as a team, and we know we have to make things better."
Elsewhere on Saturday, Harlequins should take another stride towards a last-eight place from Pool Three by accounting for Italian minnows Zebre at the Twickenham Stoop.
Leicester, though, face a tricky Pool Two Italian job away to Treviso. They beat Treviso at Welford Road last Sunday, but only 33-25 and they were outscored in the second period.
There is a pivotal encounter for reigning European champions Leinster, who must defeat Pool Five rivals Clermont Auvergne in Dublin or be left facing early elimination.
Edinburgh, meanwhile, will look to give Scottish rugby a timely boost when they entertain Racing Metro on Friday night. The Pool One encounter at Murrayfield gives Edinburgh an opportunity to avenge last weekend's 19-9 defeat in Paris.
Edinburgh and Glasgow have lost six games between them in Europe this season, while Edinburgh have yet to score a try, and it is less than a month since the national team were beaten at home by Tonga, which prompted Andy Robinson's resignation as head coach.
Edinburgh coach Michael Bradley has made eight changes, including a return for fit-again centre Ben Cairns, who has not played since suffering a knee injury 15 months ago. Cairns' fellow centre Ben Atiga is also back from injury, along with Fijian back-row forward Netami Talei and Georgian number eight Dimitri Basilaia, who is on the bench.
In the Amlin Challenge Cup, Bath and Gloucester should strengthen their quarter-final claims by accounting for Calvisano and London Irish, respectively, on Saturday.