Moto2 title contender Julian Simon put the European Suter chassis at the top of the Friday practice timesheets for the Japanese Grand Prix at Motegi.
The Aspar rider suffered a lowside at the end of the session, but still finished 0.124sec in front of world championship leader Toni Elias, riding in the home event for his chassis manufacturer Moriwaki.
Elias, who is 76 points in front of fellow Spaniard Simon with five rounds to go, has a slim chance of claiming the inaugural 600cc grand prix crown on Sunday.
Alex de Angelis was third fastest on the JiR MotoBI entry, with the on-form Scott Redding fourth for Marc VDS Suter.
Yonny Hernandez used his Supermoto skills to claim fifth on the stop-go circuit, with Simone Corsi (JiR) sixth and local star Yusuke Teshima seventh for TSR.
Wild-card Shogo Moriwaki - riding his family's Moto2 chassis, run by their own team – ran in the top ten for much of the session, but eventually slipped back to 18th.
Friday practice - Motegi:
1. Simon (Suter) 1m 54.203s
2. Elias (Moriwaki) +0.124s
3. de Angelis (MotoBI) +0.253s
4. Redding (Suter) +0.255s
5. Hernandez (BQR) +0.547s
6. Corsi (Motobi) +0.848s
7. Teshima (TSR) +0.904s
8. Aegerter (Suter) +0.939s
9. Talmacsi (Speed Up) +0.952s
10. Corti (Suter) +1.033s