Marc Marquez began the Le Mans MotoGP weekend on top as he set the Friday morning practice pace.
The championship leader led a Honda one-two ahead of team-mate Dani Pedrosa.
Marquez's early benchmark had been beaten by LCR Honda rider Stefan Bradl, but the Spaniard reclaimed the top spot with two rapid mid-session laps culminating in a 1m34.383s.
That would have been sufficient for first place even if he had not improved to 1m34.328s with his very last lap of the morning.
Pedrosa also found time on his final lap to beat the Yamahas of Valentino Rossi and Jorge Lorenzo to second.
Alvaro Bautista took fifth ahead of Bradl, with Andrea Dovizioso the top Ducati in seventh.
Bradley Smith crashed at the start of the session, losing control of his Tech 3 Yamaha into the Chemin aux Boeufs esses at the end of the back straight.
The Briton had to abandon his primary bike but was unhurt and able to rejoin on his spare later on.
The field is down to 22 bikes this weekend as Ioda is absent.
Regular rider Danilo Petrucci fractured a wrist in a warm-up crash at Jerez a fortnight ago, and his planned replacement Luca Scassa then sustained a leg injury in testing this week.
Pos Rider Team Time Gap Laps 1. Marc Marquez Honda 1m34.328s 20 2. Dani Pedrosa Honda 1m34.517s +0.189s 21 3. Valentino Rossi Yamaha 1m34.581s +0.253s 19 4. Jorge Lorenzo Yamaha 1m34.598s +0.270s 18 5. Alvaro Bautista Gresini Honda 1m34.653s +0.325s 20 6. Stefan Bradl LCR Honda 1m34.734s +0.406s 21 7. Andrea Dovizioso Ducati 1m34.875s +0.547s 20 8. Pol Espargaro Tech 3 Yamaha 1m34.929s +0.601s 22 9. Andrea Iannone Pramac Ducati 1m34.933s +0.605s 21 10. Aleix Espargaro Forward Yamaha 1m35.073s +0.745s 16 11. Bradley Smith Tech 3 Yamaha 1m35.431s +1.103s 17 12. Cal Crutchlow Ducati 1m35.438s +1.110s 20 13. Hiroshi Aoyama Aspar Honda 1m35.638s +1.310s 20 14. Nicky Hayden Aspar Honda 1m35.762s +1.434s 19 15. Colin Edwards Forward Yamaha 1m36.149s +1.821s 18 16. Yonny Hernandez Pramac Ducati 1m36.458s +2.130s 19 17. Scott Redding Gresini Honda 1m36.663s +2.335s 17 18. Mike di Meglio Avintia FTR-Kawasaki 1m37.026s +2.698s 20 19. Karel Abraham Cardion Honda 1m37.120s +2.792s 14 20. Hector Barbera Avintia FTR-Kawasaki 1m37.404s +3.076s 19 21. Broc Parkes PBM Aprilia 1m38.933s +4.605s 16 22. Michael Laverty PBM Aprilia 1m39.055s +4.727s 17