Carlos Sainz Jr completed a Formula Renault 3.5 double at Spa, cruising to victory after his main rival Oliver Rowland hit trouble in the pits.
Rowland had chased Sainz throughout the first stint, with the gap fluctuating as they traded fastest laps and left everyone else behind.
By the time they came in together for their mandatory pitstops Rowland was within one second of the leader, but his clutch failed to engage as he made his stop, cutting the engine and and costing him 11 seconds.
That promoted Will Stevens to second, while Rowland rejoined fourth behind Richie Stanaway.
The Briton could do nothing about the FR3.5 returnee, but in the end he didn't have to, as Stanaway was penalised 20 seconds for making his pitstop outside of the designated window.
Stanaway pitted at the end of lap 12 (the last lap of the window), but as he crossed the start/finish line in the pits that was counted as stopping on lap 13.
Pierre Gasly jumped Norman Nato for fifth on the road during the pitstops, but the Red Bull junior could not quite get onto the tail of Stanaway and Rowland.
Stanaway's penalty - on his comeback two years after injuring himself at the same circuit in his last FR3.5 meeting - dropped him from a podium place to the lower reaches of the points.
Results - 21 laps:
Pos Driver Team Time/Gap
1. Carlos Sainz Jr DAMS 43m24.524s
2. Will Stevens Strakka +12.330s
3. Oliver Rowland Fortec +15.045s
4. Pierre Gasly Arden +15.888s
5. Norman Nato DAMS +23.181s
6. Jazeman Jaafar ISR +26.953s
7. Matias Laine Strakka +27.434s
8. Richie Stanaway Lotus +34.420s
9. Meindert van Buuren Pons Racing +45.751s
10. Marco Sorensen Tech 1 +45.937s
11. Marlon Stockinger Lotus +46.686s
12. Will Buller Arden +47.099s
13. Roberto Merhi Zeta Corse +57.776s
14. Beitske Visser AVF +1m02.128s
15. Oscar Tunjo Pons Racing +1m10.605s
16. Roman Mavlanov Zeta Corse +1m21.931s
Luca Ghiotto Draco 15 laps
Sergey Sirotkin Fortec 6 laps
Pietro Fantin Draco 0 laps
Zoel Amber AVF 0 laps