San Carlo Honda Gresini's Marco Melandri got a good start to hold sixth at the end of lap one, a position he retained at the flag for his best result of the season, while home hero Randy de Puniet collected seventh on his LCR Honda.
Top rookie was Hector Barbera, who rode an aggressive race to a commendable eighth, just in front of countryman Aleix Espargaro (Pramac). The two other 250 graduates, Marco Simoncelli and Hiroshi Aoyama were tenth and eleventh.
Twelfth placed Colin Edwards was the only Tech 3 rider to reach the flag, in any race, on Sunday. The French-based team's Moto2 riders both crashed out of their race, while Ben Spies did likewise - for his second DNF in a row - while holding eleventh on lap 7 of the MotoGP main event.
The lone starting Suzuki of Loris Capirossi also crashed out at around the same time, while the injured Mika Kallio (Pramac) rode to a lonely 13th and last.
All of which means that Lorenzo is now nine points ahead of Rossi after three of 18 rounds, with Stoner only 13th heading into the Italian Grand Prix - a home round for Ducati and Rossi.
French Grand Prix:
7. de Puniet