Nicolo Bulega ended a soaking Friday at Motegi fastest of all, while world champion elect Joan Mir struggled for pace.
The 2.98-mile Motegi circuit was left saturated by heavy overnight rain when the first 40-minute session go underway this morning.
This did not deter the Sky VR46 duo, however, with Bulega and team-mate Andrea Migno riding in formation for the duration of the session.
A 2m09.577s from Bulega put him 0.128 seconds clear of Migno at the chequered flag, while Romano Fenati – who is gunning for his first podium finish at Motegi this weekend – completing the top three on the combined times.
Fenati put in a late effort of 2m10.628s to top the standings in the afternoon session, though improvements in laptime from the first session were few and far between in second practice despite the slightly better conditions.
Red Bull KTM Ajo’s Niccolo Antonelli enjoyed a strong Friday. The Italian – who has not scored a top six finish in over a year – was just 0.006s shy of Fenati‘s time in the afternoon having led the session for a time, and this moved him up to fifth on the combined times.
Aron Canet slotted into fourth on his Estrella Galicia 0,0 Honda in both session, with CIP Mahindra’s Manuel Pagliani sixth fastest ahead of Adam Norrodin, who crashed at the final corner in the opening stages of second practice.
Nakarin Atiratphuvapat has proven to be a wet weather specialist this season on his Team Asia Honda, and the Thai rider continued to impress in the treacherous conditions with the ninth fastest time of the day ahead of Tatsuki Suzuki.
Bo Bendsneyder was shuffled back to 11th on the combined standings after a nightmare afternoon session, in which the Dutch rider crashed twice at Turn 5 – his first a lowside on his outlap, with the second a highside in the closing stages.
Ayumu Sasaki was 12th on the combined timesheets after a fall at Turn 3 at the end of the second session, with Albert Arenas improving to 13th in the afternoon ahead of Enea Bastianini and John McPhee, who also suffered a late tumble.
Twitter: Not something we’re used to seeing this year!
@Joanmir36 in the gravel unhurt. #JapaneseGP https://t.co/o0IM3u2XgL (@MotoGP)
The big shock of the day came in the form of championship leader Joan Mir, who was 2.5s off the pace down in 17th on the combined times.
Off the pace in both sessions, Mir – who can clinch the Moto3 title this weekend after taking an 80-point lead at Aragon – also took a rare trip into the gravel trap when he crashed at Turn 3 with six minutes to go.