Spanish Ducati rider Marquez laid down a best lap of 1 minute 44.95 seconds in unseasonably warm conditions at Motegi, where temperatures were close to 30°C.

That was 0.102 seconds slower than Bagnaia, with defending world champion Jorge Martin second-fastest, 0.093 seconds behind the quickest time.

Marquez is looking to win his seventh world title in Japan this weekend after dominating the competition with 11 Grand Prix wins this season already.

He can seal the deal if he finishes the weekend with at least three more points than his brother and nearest championship rival Alex Marquez.

Alex Marquez was 15th-fastest in practice, 0.643 seconds slower than Bagnaia.

Marc Marquez has a huge championship lead over his brother and still has five weekends left to clinch the title if he fails to get the job done in Japan.

His 512 championship points are already a single-season record for a MotoGP rider.

Aprilia’s Marco Bezzecchi, who finished second behind Marc Marquez at the San Marino Grand Prix two weeks ago, had a nightmare first practice, crashing twice.

First the Italian came off about 10 minutes into the session, then he took another tumble half an hour later to end his morning practice on a low note.

Bezzecchi is looking to overtake Bagnaia and move into third place in the overall standings after a string of good recent results.

Trackhouse’s Raul Fernandez also crashed in the first 10 minutes of the session.

Franco Morbidelli, Jack Miller and Enea Bastianini all came off in the final minutes.