Marco Bezzecchi and Jorge Martin return to first and second.
Aprilia has never had a podium at Motegi but are starting the weekend strongly.
With the chequered flag waving Marc Marquez puts his Ducati at the top of the FP1 timesheets with a 1m 44.073s.
Aprilia team-mates Jorge Martin and Marco Bezzecchi complete the top three.
Lap times continue to tumble, with Martin now back on top from title rivals Marc Marquez and Bezzecchi.
Marc Marquez goes to the top for the first time with 2mins to go.
Marco Bezzecchi and Jorge Martin return to first and second.
Aprilia has never had a podium at Motegi but are starting the weekend strongly.
Fabio Quartararo and Diogo Moreira jump to second and third with five minutes to go...
1. Alex Marquez 1m 44.631s
2. Fabio Quartararo +0.027s
3. Diogo Moreira +0.234s
4. Marco Bezzecchi +0.406s
5. Francesco Bagnaia +0.413s
6. Jorge Martin +0.431s
7. Ai Ogura +0.451s
8. Marc Marquez +0.489s
9. Fermin Aldeguer +0.724s
10. Toprak Razgatlioglu +0.729s
11. Somkiat Chantra +0.894s
12. Pedro Acosta +0.904s
13. Fabio Di Giannantonio +0.924s
14. Brad Binder +0.969s
15. Johann Zarco +1.072s
16. Raul Fernandez +1.386s
17. Maverick Viñales +1.389s
18. Enea Bastianini +1.401s
19. Franco Morbidelli +1.522s
20. Luca Marini +1.550s
21. Alex Rins +1.685s
22. Jack Miller +2.197s
Bad news from HRC:
"Unfortunately [Takaaki Nakagami] has sustained a fracture to his left collarbone and has been declared unfit for the weekend."
This was due to be not only his final 1000cc MotoGP race, but last MotoGP race for the foreseeable future, with all wildcards banned from 2027.
It's also a concern for Honda's 850cc testing plans...
Change at the top with Alex Marquez putting Gresini Ducati fastest with a 1m 44.631s.
Although he's been out on track since his earlier highside, Nakagami has not yet set a lap time.
12mins to go:
1. Marco Bezzecchi 1m 45.037s
2. Francesco Bagnaia +0.007s
3. Jorge Martin +0.025s
4. Marc Marquez +0.083s
5. Alex Marquez +0.333s
6. Pedro Acosta +0.498s
7. Fermin Aldeguer +0.576s
8. Diogo Moreira +0.889s
9. Raul Fernandez +0.980s
10. Maverick Viñales +0.983s
11. Enea Bastianini +0.995s
12. Somkiat Chantra +1.092s
13. Franco Morbidelli +1.116s
14. Luca Marini +1.144s
15. Toprak Razgatlioglu +1.196s
16. Fabio Quartararo +1.212s
17. Jack Miller +1.791s
18. Johann Zarco +1.919s
19. Fabio Di Giannantonio +2.006s
20. Ai Ogura +2.199s
21. Alex Rins +2.226s
22. Brad Binder +3.245s
Marc Marquez moves up to fourth on the timesheets, behind Bezzecchi, Bagnaia and Martin.
It's now an Aprilia one-two with Martin behind Bezzecchi.
1. Marco Bezzecchi 1m 45.037s
2. Francesco Bagnaia +0.924s
3. Raul Fernandez +0.980s
4. Jorge Martin +0.983s
5. Somkiat Chantra +1.092s
6. Pedro Acosta +1.159s
7. Fermin Aldeguer +1.650s
8. Johann Zarco +1.919s
9. Fabio Di Giannantonio +2.006s
10. Maverick Viñales +2.065s
11. Toprak Razgatlioglu +2.379s
12. Enea Bastianini +3.019s
13. Marc Marquez +3.296s
14. Jack Miller +3.469s
15. Alex Marquez +4.273s
16. Diogo Moreira +4.988s
17. Franco Morbidelli +5.742s
18. Ai Ogura +5.768s
19. Alex Rins +7.714s
Bezzecchi hasn't let the earlier scare phase him - he's now fastest from last year's double winner Francesco Bagnaia.
This was Marco Bezzecchi's early scare on the damp track at Turn 11. Takaaki Nakagami had a nasty highside shortly after:
Most riders are now heading out on track.
Halfway through FP1:
1. Somkiat Chantra 1m 46.129s
2. Raul Fernandez +1.197s
3. Toprak Razgatlioglu +1.287s
4. Marco Bezzecchi +2.256s
5. Jack Miller +2.377s
6. Johann Zarco +2.746s
7. Francesco Bagnaia +3.128s
Maverick Vinales is heading out for his first laps, joined by the likes of Pecco Bagnaia, Marco Bezzecchi and title leader Jorge Martin.
Marc Marquez is still in the pits.
Good news. Despite the brutal highside, Takaaki Nakagami is leaving the pits to restart the session.
Conditions look to be getting brighter, but Chantra, Miller and Razgatlioglu are still the only riders on track.
The Thai rider, who now races for the factory Honda WorldSBK team alongside Jake Dixon, is replaced at the top by Razgatlioglu with just over half an hour to go.
However, lap times are around five seconds off the lap record due to the conditions.
Just to confirm, the HRC riders are using their normal Castrol livery at the moment. The special 60th anniversary livery will be used on Sunday.
The scare for Bezzecchi and incident for Nakagami looks to have prompted most riders to return to the pits.
Only Chantra, Jack Miller and Toprak Razgatlioglu are still on track.
Disastrous start to the weekend for HRC wildcard Takaaki Nakagami who is slammed into a big highside, also at the apex of Turn 11.
The Japanese walks away holding his upper left arm.
The green lights are on, and MotoGP FP1 begins.
Tech3's Maverick Vinales heads out for his first official MotoGP laps since Sachsenring, and HRC stand-in Somkiat Chantra his first MotoGP laps since Valencia last year.
The white and red rain flags are waving and Marco Bezzecchi has a scare when the rear of his Aprilia steps out at Turn 11.
Just a few minutes to go before the start of FP1, and there are rain spots in the air.