Maverick Vinales scored the second win of his 125cc career in a rain-truncated race at Assen, which championship leader Nico Terol had to sit out due to hand injuries sustained on Saturday.
Aspar rider Terol was unable to take up his eighth place on the grid as he required surgery after crashing in both morning practice and qualifying yesterday, giving his rivals a golden opportunity to carve a chunk from the hitherto dominant Spaniard's points lead.
Although the race was declared officially dry, drizzle began falling from the early stages. That led to an astounding lead battle in the slightly slippery conditions, with up to eight bikes vying for first place and racing four and five abreast into the corners as they scrabbled for whatever grip was available on the damper parts of the circuit.
Polesitter Vinales kept a relatively low profile amid this initial madness, falling to ninth while the likes of Efren Vazquez, Sandro Cortese, Sergio Gadea and Luis Salom disputed the lead. But as the race progressed and the weather got worse, Vinales picked his way forward and got back in front.
Then as the rain increased and riders behind began frantically waving for the race to be stopped, Vinales simply got his head down and pushed harder, breaking away from the field. When the red flags were put out on lap 14 - late enough in the distance to avoid the need for a restart - the young Spaniard was nearly three seconds clear and duly claimed victory.
The hard-charging Salom secured his maiden podium in second plae, with Vinales' teammate Gadea making it an all-Spanish rostrum, just ahead of Ajo teammates Johann Zarco and Danny Kent. Vazquez and Jonas Folger, who were also major factors in the early lead dice, finished seventh and eighth.
Local favourite Jasper Iwema flew through the order from 33rd on the grid, getting up to 17th before tangling with Adrian Martin. He rejoined but retired in a second accident.
Results - 14 laps:
Pos Rider Team/Bike Time/Gap
1. Maverick Vinales Blusens Aprilia 25m04.147s
2. Luis Salom RW Aprilia + 2.555s
3. Sergio Gadea Blusens Aprilia + 2.655s
4. Sandro Cortese Germany Aprilia + 3.670s
5. Johann Zarco Ajo Derbi + 3.903s
6. Danny Kent Ajo Aprilia + 4.469s
7. Efren Vazquez Ajo Derbi + 8.828s
8. Jonas Folger Ajo Aprilia + 10.416s
9. Marcel Schrotter Mahindra + 10.791s
10. Hector Faubel Aspar Aprilia + 13.238s
11. Alexis Masbou Caretta KTM + 15.255s
12. Simone Grotzkyj Phonica Aprilia + 16.061s
13. Danny Webb Mahindra + 25.420s
14. Zulfahmi Khairuddin Ajo Derbi + 26.954s
15. Alberto Moncayo Andalucia Aprilia + 27.578s
16. Jakub Kornfeil Ongetta Aprilia + 27.886s
17. Luigi Morciano Italia Aprilia + 29.450s
18. Luca Gruenwald Freudenberg KTM + 32.367s
19. Giulian Pedone Phonica Aprilia + 33.472s
20. Peter Sebestyen Caretta KTM + 39.819s
21. Josep Rodriguez Andalucia Aprilia + 40.069s
22. Bryan Schouten Dutch Honda + 46.619s
23. Alessandro Tonucci Italia Aprilia + 47.645s
24. Francesco Mauriello WTR-Ten10 Aprilia + 47.904s
25. Harry Stafford Ongetta Aprilia + 48.341s
26. Taylor Mackenzie Phonica Aprilia + 1m03.962s
27. Joan Perello Matteoni Aprilia + 1m06.347s
28. Thomas van Leeuwen Van Leeuwen Honda + 1m10.403s
29. Jerry van de Bunt Jerrys Honda + 1m22.128s
30. Louis Rossi Matteoni Aprilia + 1m23.063s
31. Sturla Fagerhaug WTR-Ten10 Aprilia + 1m25.572s
32. Ernst Dubbink RV Honda + 1m33.434s
33. Adrian Martin Aspar Aprilia + 3 laps
Jasper Iwema Ongetta Aprilia 12 laps
Niklas Ajo TT Motion Aprilia 3 laps