Marc Marquez wrapped up the second win of his Moto2 career in wet conditions at Assen, and moved up to second in the championship in the process.
Series leader and polesitter Stefan Bradl crashed out near the end of the race, but remains 57 points ahead of Marquez in the standings.
Bradl (Kiefer Kalex) struggled from the outset in the wet race, steadily slipping down the order from pole and falling as low as 13th. He managed to get back up to eighth before sliding out at the chicane in the closing stages.
Simone Corsi, Bradley Smith and Marquez set the early pace, although as conditions improved slightly Corsi would begin to fade, eventually tumbling right back to 14th.
Kenan Sofuoglu then moved up to join Smith and Marquez's lead battle, with Yuki Takahashi shadowing them. All of the first three took turns in front amid some very close racing on the greasy track.
Takahashi picked his way through to second, only to crash on lap 20 of 24. Marquez was leading at that stage, and the accident gave him a little breathing space, as he inched away to win by 2.3 seconds over Sofuoglu - the Technomag-CIP rider securing his first Moto2 podium. Smith fell back from Sofuoglu as he claimed a second straight top-three finish in third.
Anthony West showed his usual outstanding wet weather form to come through from 21st to fourth on the MZ, a short distance ahead of the battling Alex de Angelis and Mattia Pasini.
Results - 24 laps: Pos Rider Team/Bike Time/Gap 1. Marc Marquez Catalunya Suter 44m30.409s 2. Kenan Sofuoglu Technomag-CIP Suter + 2.397s 3. Bradley Smith Tech 3 + 6.418s 4. Anthony West MZ + 22.803s 5. Alex de Angelis JIR Motobi + 25.882s 6. Mattia Pasini Ioda FTR + 26.851s 7. Esteve Rabat Blusens-STX FTR + 28.125s 8. Thomas Luthi Paddock Suter + 28.712s 9. Randy Krummenacher Kiefer Kalex + 29.744s 10. Max Neukirchner MZ + 39.767s 11. Alex Baldolini Forward Suter + 47.158s 12. Andrea Iannone Speed Master Suter + 50.846s 13. Yonny Hernandez Blusens-STX FTR + 57.118s 14. Simone Corsi Ioda FTR + 1m00.775s 15. Claudio Corti Italtrans Suter + 1m06.310s 16. Aleix Espargaro Pons Kalex + 1m06.764s 17. Michele Pirro Gresini Moriwaki + 1m06.823s 18. Dominique Aegerter Technomag-CIP Suter + 1m16.296s 19. Ricard Cardus QMMF Moriwaki + 1m21.524s 20. Carmelo Morales G22 Moriwaki + 1m22.289s 21. Kev Coghlan Castello FTR + 1m38.161s 22. Michael van der Mark EAB Ten Kate + 1m41.888s 23. Javier Fores Aspar Suter + 1m42.189s 24. Scott Redding Marc VDS Suter + 1 lap 25. Mashel Al Naimi QMMF Moriwaki + 1 lap 26. Robertino Pietri Italtrans Suter + 1 lap Retirements: Stefan Bradl Kiefer Kalex 20 laps Steven Odendaal MS Suter 20 laps Yuki Takahashi Gresini Moriwaki 19 laps Pol Espargaro Speed Up FTR 19 laps Kenny Noyes Avintia-STX FTR 19 laps Xavier Simeon Tech 3 18 laps Mika Kallio Marc VDS Suter 13 laps Axel Pons Pons Kalex 7 laps Ratthapark Wilairot SAG FTR 5 laps Valentin Debise Speed Up FTR 5 laps Santiago Hernandez SAG FTR 3 laps Mike di Meglio Tech 3 0 laps Jules Cluzel Forward Suter 0 laps