The top two go head-to-head in Pool 2 when Newcastle Falcons host Toulon at Kingston Park on Thursday evening.
The hosts kicked off their 2011/12 European campaign with victory at home to Lyon before collecting a bonus-point win in Italy against Petrarca Padova.
Toulon are level on points with the Falcons at the helm of their Amlin Pool after victories over the same two sides.
Falcons will go into the match in positive mood following their impressive victory over Gloucester in the English Premiership last weekend, whilst Toulon.
Lyon Rugby v Petrarca Padova
(Saturday December 12)
In contrast Lyon and Petrarca meet at Matmut Stadium, each looking to claim their first victory of the European season.
Both suffered defeats in the opening two rounds and will be looking to claim their first scalps as the sides meet in the first of back-to-back games.
Domestically Lyon go into European action confident following their victory over Perpignan and the same can be said of Petrarca Padvoa, who beat San Gregorio Catania at the weekend.