Glasgow Warriors, with Grayson Hart a halfback replacement, edged Scarlets 9-6. Otago's Michael Collins turned out at fullback for Scarlets.
Toulon beat Leinster 20-16 in Dublin. Ma'a Nonu was again at second five, while Tom Taylor kicked two important goals off the bench.
Former Counties Manukau Steeler and Chief Fritz Lee scored a try from No 8 as Clermont thrashed Thomas Waldrom's Exeter Chiefs 42-10, the latter copping a yellow card.
There were no less than nine New Zealanders in action at Northampton, where the home side and Racing-Metro battled to a 9-all stalemate. Dan Carter kicked three penalty goals for the Parisians.
A try to wing Fetu'u Vainikolo was nowhere near enough for Oyonnax, who fell 55-13 at Saracens. Former Taranaki and Tonga No 8 Samuela Vunisa scored a brace for Sarries.
Another former Taranaki pair in Jayden Hayward and Chris Smylie combined in the halves for Treviso, who lost 40-14 to Stade Francais.
In the second-tier Challenge Cup, fullback Mils Muliaina scored a late try as his Italian club Zebre beat Jason Eaton's La Rochelle 25-5. Brive comfortably beat Robbie Malneek's Enisei 33-3, while Montpellier edged Cardiff Blues 23-22. Rey Lee-Lo (12) and Jarrad Hoeata (4) were in the Cardiff starting XV.
There was plenty of Kiwi impact in Grenoble, as the home side defeated Agen 48-45. Former Chiefs and Bay of Plenty wing Tino Nemani scored a brace, while second five Nigel Hunt also crossed the tryline.
Loosies Mike Coman and new Scottish international John Hardie, plus No 10 Phil Burleigh, all appeared for Edinburgh in their 18-15 win over Ben Franks' London Irish.
Conrad Smith made his long-awaited debut, off the bench, as Pau crashed 17-34 at home to Nick Crosswell's Dragons. Colin Slade slotted a conversion for the vanquished.
First five Ben Botica, standing in for Nick Evans, helped himself to 19 points for Harlequins in their 59-7 shellacking of Calvisano. Winston Stanley played at centre for Quins.
Centre Johnny Leota and No 8 Viliami Fihaki both scored tries in Sale Sharks' 31-10 win over David Smith's Castres.
Newcastle Falcons, with Tana Takalua at halfback and loose forward Richard Mayhew entering the fray as a sub, defeated George Naoupu's Connacht 29-5.
The postponed European games from last month will be played on the weekend of January 8-10.