Dovizioso ends Motegi first practice on top

Dovizioso used the extra-soft tyre available to Ducati to put in a 1m45.140s lap late in the afternoon session.

That upstaged morning pacesetter and previous practice two leader Jorge Lorenzo by 0.440 seconds.

The same margin almost covered the next eight bikes, with Lorenzo's Yamaha 0.057s ahead of Stefan Bradl's third-placed LCR Honda.

Championship leader Marc Marquez had another tough session after his morning crash, coping with several unsteady moments on his way to sixth, behind Honda team-mate Dani Pedrosa and the second Yamaha of Valentino Rossi.

Tech 3 duo Pol Espargaro and Bradley Smith took seventh and eighth, while Andrea Iannone and Cal Crutchlow completed the top 10.

Crutchlow is yet to secure his place in Q2 despite that result, as Yonny Hernandez's rapid practice one time is currently sufficient to take him straight through to final qualifying.

Aragon podium finisher Aleix Espargaro is another rider who will have to improve on Saturday morning to avoid having to go through Q1. The Forward rider was only 13th on Friday afternoon.

Local rider Hiroshi Aoyama had the only crash of practice two, falling at the first corner late on.