Bryn Evans' try was not enough to prevent Sale Sharks falling 41-18 to Brendon O'Connor's Leicester. Mike FitzGerald came off the Tigers' bench, while Johnny Leota was a Sharks' replacement.
Bristol's Kiwi contingent of Jason Woodward, Alby Mathewson, Mark Sorenson, Tusi Pisi and Siale Piutau fell 27-9 to Saracens, for whom Lions tourist Owen Farrell kicked three goals.
Nick Evans made his final appearance at the Twickenham Stoop one to remember with 22 points in Quins' 32-22 defeat of leaders Wasps. The former All Blacks No 10 has had nine productive seasons with the club and bowed out with a classy display. Mat Luamanu and Alofa Alofa were among his teammates.
Jimmy Gopperth, another former Blues No 10, slotted three goals, while Nathan Hughes and Alapati Leiua came off the pine.
In the Guinness PRO12, John Hardie's Edinburgh edged the Dragons 24-20.
A try to Brendon Leonard, subbed on for Lions No 9 Rhys Webb, helped Ospreys to the cusp of the semifinals with a 24-10 win over Ulster. Kieron Fonotia was at centre for the victors. The playoffs fate of Ulster, who started Charlie Piutau and Sean Reidy, is now out of their hands.
Munster defeated Dean Budd's Treviso 34-14. Francis Saili set up a try, while Tyler Bleyendaal kicked four goals. Rhys Marshall started at hooker for Munster.
Wayne Pivac won his coaching battle with Pat Lam as Scarlets beat Connacht 30-8 in Galway, Johnny McNicholl scoring a try from fullback. Hadleigh Parkes was back at No 12, while for Connacht, Jake Heenan and Dominic Robertson-McCoy were in the starting XV.
Gareth Anscombe helped himself to 20 points as Cardiff Blues beat Kurt Baker's Zebre 30-24. That haul consisted of a try, three conversions and three penalties. No 8 Nick Williams was sinbinned. Jarrad Hoeata, Rey Lee-Lo and Willis Halaholo also featured.
Brian Alainu'uese's Glasgow lost narrowly, 31-30, to Leinster, for whom Michael Bent and Jamison Gibson-Park were injected off the bench.
In the French Top 14, things are tight for the playoffs aspirations of Racing-Metro, who lost their Parisian derby with Stade Francais 27-23, though Casey Laulala and Ben Tameifuna scored tries and Dan Carter kicked 13 points.
Things are also on a knife-edge for Pau with just this weekend's final round to play out. Tom Taylor, from fullback, slotted three goals in their 32-17 win over Brive. His teammates included Conrad Smith, Taniela Moa, Jamie Mackintosh and Daniel Ramsay.
David Smith's Castres smashed neighbours Toulouse 52-7. Luke McAlister scored all the points for the former champs.
Victor Vito picked up a brace as La Rochelle beat Montpellier 40-37 in what the French would call 'le choc au sommet.' Uini Atonio and Jason Eaton also featured for the Top 14 leaders.
Ma'a Nonu's Toulon will be in the playoffs after they won 26-13 at Bordeaux-Begles, with Lions tourist Leigh Halfpenny kicking 16 points. It was noted that former Wallaby 'bad boy' James O'Connor, whose primary schooling was in west Auckland, was a replacement for Toulon. The home side had Hugh Chalmers, Luke Braid and Simon Hickey in their squad.
Bayonne's Kade Poki scored a try in his club's 43-35 win over a Grenoble outfit that included Sona Taumalolo, Nigel Hunt and Tino Nemani.
Benson Stanley's Clermont beat Lyon 23-20, Mike Harris kicking three goals for the latter, while alongside him were Josh Bekhuis, Ti'i Paulo, Taiasina Tuifua, Hosea Gear and Rudi Wulf.