Adrian Quaife-Hobbs converted pole position into his fourth victory of the season at round five of the Auto GP World Series at Algarve.
The Briton was overtaken for the lead into Turn 1 by Campos Racing's Facu Regalia, but outbraked the Argentinian at the same spot on lap two.
Once ahead, Quaife-Hobbs demonstrated strong pace on used medium compound tyres, and was only troubled passing a stubborn, out of sequence, Francesco Dracone (Virtuosi UK) five laps from home.
Despite the slight scare, Quaife-Hobbs recorded a dominant nine-second margin of victory, the Super Nova racer extending his lead in the drivers' standings to 52 points over Pal Varhaug in the process.
The Norwegian's qualifying was disrupted by fuel issues that left him fifth on the grid, but the Virtuosi UK driver used an early pitstop to progress to second at the chequered flag.
"It's difficult to rank your wins, but I thought that was a really good race," said Quaife-Hobbs. "I had only managed to do four laps before suffering graining on my tyres before the race, but we managed to go nine laps on used tyres. It was unexpected. I would have stayed out longer but I wanted to cover off Pal in case there was a safety car."
Euronova Racing driver Sergey Sirotkin made Varhaug work hard for second. The fast- starting Russian exited the pitlane from his mandatory tyre change marginally ahead of Varhaug on lap 10, but on cold tyres was overtaken on the uphill run out of Turn 6.
Formula Abarth Europe champion Sirotkin maintained the fight, finishing 0.590s adrift of Varhaug at the chequered flag.
Quaife-Hobbs' Super Nova team-mate Victor Guerin made a relatively slow getaway from third on the grid. The Brazilian entered Turn 1 in fifth, but recovered ground on MLR 71 racer Sergio Campana when the Italian's early stop on lap five failed to pay off.
Early leader Regalia dropped behind Sirotkin when he ran offline, and would end the afternoon in sixth.
Results - 18 laps: Pos Driver Team Time/Gap 1. Adrian Quaife-Hobbs Super Nova 29m24.999s 2. Pal Varhaug Virtuosi UK + 9.044s 3. Sergey Sirotkin Euronova + 9.634s 4. Victor Guerin Super Nova + 13.573s 5. Sergio Campana MLR 71 + 15.309s 6. Facu Regalia Campos + 16.833s 7. Daniel de Jong Manor MP + 17.283s 8. Chris van der Drift Manor MP + 18.143s 9. Juan Carlos Sistos Zele + 27.887s 10. Giancarlo Serenelli Ombra + 31.322s 11. Antonio Spavone Euronova + 41.759s 12. Maxim Snegirev Campos + 52.007s 13. Francesco Dracone Virtuosi UK + 55.729s Retirements: Sten Pentus Zele 13 laps Giuseppe Cipriani Campos 0 laps Michele la Rosa MLR 71 0 laps