Stade Francais Paris are in pole position at the top of Pool 5 but they will have one eye on French rivals Grenoble who are only four points behind them after three rounds of the competition.
The French capital side are still unbeaten in this season's Amlin Challenge Cup after their hard-fought 37-23 victory away in Italy over part-timers I Cavalieri Prato in Round Three.
Francis Fainifo was the try hat-trick hero in Round 3 and the Parisians will be looking to cement their position as probable quarter-finalists and to pull away from Grenoble in the table when they host the Italian outfit.
French rivals Grenoble will be looking to keep up the pressure on Stade and build on their 20-9 home victory in the first leg of their own double-header over Premiership new boys London Welsh.
The Welsh Exiles, who are playing their first season of European rugby, will provide a warm welcome to Grenoble at the Kassam Stadium in Oxford on Saturday afternoon.