Three-time European Cup champions Toulouse face a daunting trip to Bath next weekend to try and save their place in the knockout stages after they lost to Glasgow and Bath beat Newport Gwent-Dragons on Sunday.
Toulouse were beaten 33-26 while Bath held on to win 15-12.
Stade Francais, who had been given a lifeline by Harlequins’ defeat to Ulster on Saturday, saw their hopes extinguished by losing 31-17 to Scarlets on Sunday.
Despite Newport’s defeat, it was a good weekend for Welsh clubs, epitomized by Cardiff Blues’ defeat of Gloucester, who went down 16-12 at home.
Cardiff joined Munster and Harlequins in the last eight.
However, all eyes will be on Toulouse’s clash with Bath next weekend after the English club ensured a dramatic meeting after defeating Newport.
Toulouse’s defeat puts them in a precarious position as only the six group winners and two best runners-up progress to the quarter-finals.
Toulouse had fought back brilliantly after the break having trailed 23-3 with Jean-Baptiste Elissalde scoring nine points followed by a penalty try and then a touchdown by Vincent Clerc four minutes from the end to set up a spine tingling finale.
Wasps, the 2004 and 2006 champions, are also in danger of missing out. They defeated Pool Two leaders Leinster 19-12 at Twickenham but allowed the Irishmen to leave with a vital bonus point which could be enough to see them through when they entertain rock-bottom Castres in the last group game next week.
Leinster beat Wasps 41-11 in the teams’ first meeting and they will qualify should the two sides finish on level points.
Wasps’ Serge Betsen scored the only try of the game but the reliable boot of Felipe Contempomi kept Leinster in touch.
Perpignan beat Pool Three tabletoppers Ospreys 17-15 but were still eliminated as Leicester humbled Treviso 52-0.
Leicester, while leapfrogging Ospreys to the top of the table, face a tough final match as they travel to Wales next weekend.