Mattias Ekstrom held off a late-race charge from Martin Tomczyk to lead home an Audi one-two at Valencia on Sunday.
Ekstrom had streaked into a comfortable lead in the first stint ahead of Bruno Spengler's Mercedes, but he came under pressure from Tomczyk in the closing stages after the German made his mandatory pitstops much later than most of the field to jump up from ninth on the grid to fight for the win.
Behind them, Spengler was promoted back into third place when Oliver Jarvis retired in the closing stages, after the Briton had also jumped the lead Mercedes in the pitstops.
Tomczyk and Jarvis were not the only Audis to make up ground during the stops, as Spengler had to defend from the 2008 Audi of Alexandre Premat at the end of the race.
Behind them, Timo Scheider completed the top five from 10th on the grid, while Paul di Resta was next up for Mercedes in sixth.
Mike Rockenfeller, who like Scheider had been ahead of Premat before the second stops, eventually came home seventh, with season-opener victor Gary Paffett eighth after a difficult afternoon.
The 2005 champion lost ground when he ran wide at the first corner, and he dropped back even further after spending most of the first lap swapping paint with Premat as they fought over sixth.
The Briton dropped as low as 10th when Miguel Molina barged his way through late in the race, but the pair's scrap became a battle for the final point when Jarvis retired with seven laps to go.
Molina's car appeared to be suffering at the end of the race, and Paffett was able to salvage a point from his race with a robust move of his own on the final lap.
Pos Driver Car Time/Gap 1. Mattias Ekstrom Audi 1h09m56.290s 2. Martin Tomczyk Audi + 0.435s 3. Bruno Spengler Mercedes + 3.547s 4. Alexandre Premat Audi + 4.614s 5. Timo Scheider Audi + 5.274s 6. Paul di Resta Mercedes + 8.639s 7. Mike Rockenfeller Audi + 12.812s 8. Gary Paffett Mercedes + 16.445s 9. Miguel Molina Audi + 17.116s 10. Jamie Green Mercedes + 18.382s 11. Susie Stoddart Mercedes + 31.041s 12. Maro Engel Mercedes + 48.037s 13. Franky Cheng Mercedes + 48.531s Retirements: David Coulthard Mercedes 38 laps Oliver Jarvis Audi 37 laps Markus Winkelhock Audi 34 laps Ralf Schumacher Mercedes 24 laps