Sean Maitland's Saracens defeated Northampton 27-25, with Lions hopeful Dylan Hartley scoring a try for the Saints, as did Ken Pisi. Ahsee Tuala, the former Steelers outside back, featured at fullback.
Worcester, who included Jackson Willison and Chris Vui, put a dent in Bath's playoffs hopes with a 25-19 upset result.
A try to Mat Luamanu, and a try and three goals to Nick Evans were insufficient for Harlequins, who fell 39-26 to Exeter Chiefs.
In the Guinness PRO12, Ulster hold fifth place, but were defeated 22-20 by Munster. Charlie Piutau and Sean Reidy turned out for the visitors, while for Munster, Tyler Bleyendaal came off the pine to kick a vital conversion.
Rhys Marshall and Francis Saili also featured.
Gareth Anscombe had an eventful time in Cardiff Blues' 35-17 win over Kieron Fonotia's Ospreys. The former Auckland and Wales No 10 scored a try, kicked five goals and incurred a yellow card.
Nick Williams scored a try, while Rey Lee-Lo, Willis Halaholo and Jarrad Hoeata all played for the Blues.
A Kurt Baker try was not nearly enough for Zebre, who were pumped 45-10 by Brian Alainu'uese's Glasgow Warriors.
Hayden Triggs' Leinster defeated Connacht 37-24, for whom Bundee Aki, Jake Heenan, Dominic Robertson-McCoy and Naulia Dawai all appeared.
Dean Budd's Treviso upset Phil Burleigh's Edinburgh 21-6.
Scarlets are still in the playoff places, after a 21-16 away win against Dragons. Johnny McNicholl was at fullback, with Hadleigh Parkes on the bench to give Lions hopeful Jonathan Davies a run at centre.
In the French Top 14, defending champs Racing-Metro are making a late run, their
10-8 win at Toulouse moving them up to fifth with three rounds to play. Dan Carter converted a penalty try and added a penalty goal, while Ben Tameifuna was sinbinned.
Other Kiwis to feature for Racing-Metro were Joe Rokocoko and Casey Laulala, with Chris Masoe off the bench. Toulouse, who are languishing in 12th position, fielded Luke McAlister, Census Johnston and Joe Tekori.
Montpellier pummelled Bayonne 61-22, with Tom Donnelly and Tanerau Latimer on the wrong side of the scoreline.
Tries to Jayden Spence and Hugh Chalmers saw Bordeaux-Begles win 22-19 at Brive. Luke Braid and Simon Hickey appeared off the bench.
