Jonas Folger claimed his first Moto3 victory with a dominant ride in tricky conditions at Brno.
Overnight rain led to a greasy, patchy surface for the start of the race, prompting some - most notably Efren Vazquez - to gamble on wets. The conditions also forced the championship's main protagonists to be cautious, the front order hugely mixed as a result.
Vazquez predictably flew in the early stages, storming into a four-second lead within two laps, but by lap four the advantage had swung to slicks and the Laglisse Honda slipped back relentlessly as the race wore on.
Folger had been the only rider to stay near Vazquez early on, and then reaped the rewards of being the most aggressive rider as conditions began to improve, often lapping two seconds faster than the rest of the field.
He disappeared down the road as a result, building a lead of 12s by the halfway mark which he maintained until the finish to claim his first series win in only his second race after replacing Alberto Moncayo at Aspar.
For a while it seemed the Czech fans would be able to welcome two home riders onto the podium, as Jakub Kornfeil (Ongetta FTR-Honda) and wildcard Mirsolav Popov (Mahindra MGP30) - who had started 29th - held second and third.
Halfway through however Sandro Cortese (Ajo KTM) and Maverick Vinales (Avintia FTR-Honda), now assured of dry conditions, began their charge, bring Luis Salom (RW Kalex-KTM) and Alex Rins (Monlau Suter-Honda) with them.
With two laps to run the quartet finally caught Kornfeil, setting up a thrilling five-way last-lap battle.
Cortese appeared to be destined for second but on the penultimate corner Salom dived down the inside to snatch second. Cortese was still able to extend his points advantage over Vinales, who finished directly behind him in fourth.
Kornfeil, who came just two laps short of securing a maiden Moto3 podium on home soil, had to settle for sixth behind Rins, while Popov fell four laps from the end.
Wildcard John McPhee (Racing Steps) had also impressed early on, jumping from 19th to fourth, but eventually dropped to 15th as conditions improved.
Results - 19 laps: Pos Rider Team/Bike Time/Gap 1. Jonas Folger Aspar Kalex-KTM 43m03.089s 2. Luis Salom RW Kalex-KTM + 5.918s 3. Sandro Cortese Ajo KTM + 5.963s 4. Maverick Vinales Avintia FTR-Honda + 6.091s 5. Alex Rins Monlau Suter-Honda + 6.490s 6. Jakub Kornfeil Ongetta FTR-Honda + 6.572s 7. Danny Kent Ajo KTM + 8.421s 8. Romano Fenati Italia FMI FTR-Honda + 13.382s 9. Miguel Oliveira Monlau Suter-Honda + 13.909s 10. Alessandro Tonucci Italia FMI FTR-Honda + 22.466s 11. Hector Faubel Aspar Kalex-KTM + 25.974s 12. Alberto Moncayo Laglisse FTR-Honda + 26.013s 13. Adrian Martin Laglisse FTR-Honda + 26.549s 14. Arthur Sissis Ajo KTM + 26.708s 15. John McPhee Steps Foundation KRP-Honda + 29.753s 16. Alexis Masbou Caretta Honda + 32.949s 17. Louis Rossi Germany FTR-Honda + 35.869s 18. Joan Olive TT Motion KTM + 40.433s 19. Luca Gruenwald Freudenberg Honda + 40.951s 20. Brad Binder RW Kalex-KTM + 41.125s 21. Alex Marquez Ambrogio Suter-Honda + 41.271s 22. Giulian Pedone Ambrogio Suter-Honda + 45.814s 23. Niccolo Antonelli Gresini FTR-Honda + 55.417s 24. Jasper Iwema FGR-Honda + 1m25.801s 25. Efren Vazquez Laglisse FTR-Honda + 1m39.559s 26. Kenta Fujii Technomag-CIP TSR-Honda + 1m44.620s 27. Luigi Morciano Ioda Italia + 2m17.928s 28. Armando Pontone Ioda + 1 lap Retirements: Zulfahmi Khairuddin Ajo KTM 14 laps Miroslav Popov Mahindra 14 laps Michael Ruben Rinaldi Caretta Honda 11 laps Toni Finsterbusch MZ-Honda 10 laps