The championship contenders took a win apiece at Nogaro as Sebastien Buemi took a narrow win ahead of a host of pursuing ASM rivals.
Buemi benefitted from second-placed Franck Mailleux stalling at the start to leap from sixth to second on lap one.
Edoardo Mortara took the lead but lost it when he was called in to serve a penalty for jumping the start.
That left Buemi defending from Kamui Kobayashi in the dying stages after the Japanese had passed Jean Karl Vernay on lap 11. Nico Hulkenberg followed him through into third.
Kobayashi made several attempts to pass Buemi but the Swiss kept his car in the right places and defended carefully to take the win. Hulkenberg always looked poised to steal a way past the pair of them but the opportunity never came.
Race one winner Romain Grosjean had moved up into fifth and made several attempts to pass Vernay, running wide on one lap, but had to settle for a pair of points ahead of Yann Clairay. The championship will now be decided at the Hockenheimring in October.