Stefan Bradl took his second Moto2 win of the season at Estoril after his title rival Andrea Iannone's gallant charge from 17th to first ended in a crash just a lap after he had finally taken the lead.
Bradl controlled the majority of the race, briefly being passed for the lead by Thomas Luthi at the start of lap five, but swiftly regaining it when Luthi then crashed his Interwetten Suter at the Parabolica later on the same lap. Having only qualified 14th, Iannone lost a further three places off the line and initially languished quietly in the midfield before repeating his Jerez performance and starting to hack his way up the order.
By lap 14, Iannone was into the top three. He then challenged Julian Simon for second, running wide at the first attempt but soon making a move stick. With four laps to go, Iannone was right with Bradl and diving into the lead into Turn 7. Bradl retaliated at the first corner only to run wide, seemingly allowing Iannone to make a break.
But half a lap later, as the Italian pushed to escape from Bradl and Simon, Iannone lost control going into the chicane and crashed. He was able to rejoin but had to settle for 13th.
Though Simon then did his utmost to deprive Bradl of victory, the Kiefer Kalex rider had the situation under control and stayed just in front on the final drag to the line.
Yuki Takahashi took an emotional third place for Gresini, just a week after the death of his younger brother Koki in a road accident in Japan.
Technomag-CIP's Dominique Aegerter scored his best Moto2 result yet in fourth. His teammate Kenen Sofuoglu had put in an early charge to briefly challenge Bradl for the lead, but later fell.
Simone Corsi flew through from 17th on the the grid to fifth, while a series of late moves got Pol Espargaro into sixth. Other charges came from Randy Krummenacher (25th to seventh), Mike di Meglio (26th to ninth) and Esteve Rabat (23rd to 10th). Alex Baldolini finished among them in eighth.
In other incidents, Claudio Corti and Michele Pirro both fell while holding sixth place, and 125cc champion Marc Marquez's fraught start to his Moto2 career continued. The Spaniard dropped from fourth on the grid to 11th on lap one, and later crashed into Scott Redding while trying to regain ground.
Results - 26 laps:
Pos Rider Team/Bike Time/Gap
1. Stefan Bradl Kiefer Kalex 44m40.765s
2. Julian Simon Aspar Suter + 0.147s
3. Yuki Takahashi Gresini Moriwaki + 6.188s
4. Dominique Aegerter Technomag-CIP Suter + 16.822s
5. Simone Corsi Ioda FTR + 17.076s
6. Pol Espargaro Speed Up FTR + 25.956s
7. Randy Krummenacher Kiefer Kalex + 26.102s
8. Alex Baldolini Forward Suter + 26.333s
9. Mike di Meglio Tech 3 + 26.636s
10. Esteve Rabat Blusens-STX FTR + 29.077s
11. Claudio Corti Italtrans Suter + 39.637s
12. Alex de Angelis JIR Motobi + 39.913s
13. Andrea Iannone Speed Master Suter + 42.466s
14. Ricard Cardus QMMF Moriwaki + 47.382s
15. Axel Pons Pons Kalex + 47.406s
16. Raffaele de Rosa G22 Moriwaki + 48.025s
17. Kenny Noyes Avintia-STX FTR + 52.538s
18. Yonny Hernandez Blusens-STX FTR + 53.478s
19. Javier Fores Aspar Suter + 53.938s
20. Mattia Pasini Ioda FTR + 56.089s
21. Marc Marquez Catalunya Suter + 1m04.697s
22. Michele Pirro Gresini Moriwaki + 1m04.890s
23. Robertino Pietri Italtrans Suter + 1m17.101s
24. Santiago Hernandez SAG FTR + 1m18.110s
25. Scott Redding Marc VDS Suter + 1m26.190s
26. Xavier Simeon Tech 3 + 1m27.600s
27. Anthony West MZ + 1m36.540s
28. Mashel Al Naimi QMMF Moriwaki + 1 lap
29. Bradley Smith Tech 3 + 2 laps
Valentin Debise Speed Up FTR 23 laps
Ratthapark Wilairot SAG FTR 21 laps
Mika Kallio Marc VDS Suter 18 laps
Aleix Espargaro Pons Kalex 18 laps
Kenan Sofuoglu Technomag-CIP Suter 17 laps
Jules Cluzel Forward Suter 11 laps
Steven Odendaal MS Suter 7 laps
Thomas Luthi Interwetten Suter 4 laps