Two of rugby's long-standing heavyweights clash on Saturday as Heineken Cup holders Leinster tackle European mainstays Biarritz.
Grenoble will try to revive their fading Top 14 play-off hopes when they visit Parc des Sports d'Aguilera in Biarritz on Friday.
The local passion surrounding Friday's ever-fiery Basque derby between Bayonne and Biarritz masks deeper concerns.
Biarritz scrum-half Dimitri Yachvili has been cited for repeatedly stamping on Racing Métro centre Henry Chavancy last Saturday.
Stade Français held on for a valuable Top 14 win over Bordeaux-Bègles on Saturday despite seeing skipper Sergio Parisse sent off.
On a day of by upsets, Top 14 leaders Toulon were thrashed 41-0 by Bordeaux-Bègles while Toulouse lost in Agen.
A clash of fixtures with the Six Nations means that France's heavyweights must travel without their European internationals this weekend....
French clubs Bayonne and Biarritz have opened talks around the possibility of forming a single Basque team for the Heineken Cup.
Toulouse and Biarritz will turn their attention to domestic action when they go head to head in the Top 14 on Friday.
Mike Brown starts at full-back and will make his 200th appearance for Harlequins in their Heineken Cup clash against Biarritz.
Mauro Bergamasco starts for Zebre against Biarritz at the Stadio XXV Aprile after being excluded from Italy's squad for the Six Nations....
Ahead of the final break before the Heineken Cup Pool run-in, Top 14 action continues as Toulon look to keep their lead at the summit....
Clermont closed the gap on Top 14 leaders Toulon on Sunday with a runaway 48-3 win at home over lowly Bayonne.
Grenoble compounded Toulouse to back-to-back defeats in the space of seven days after they beat the French giants 15-6 on Saturday
The Top 14 returns this week, with big games pitting Stade Français against Biarritz and also Perpignan facing an in-form Montpellier....
Biarritz coaches Jack Issac and Serge Milhas have been removed from their positions according to reports.
Toulon cemented their place at the top of the Top 14 standings thanks to a 39-3 win over Grenoble on Saturday.