Dani Pedrosa trimmed a little from Jorge Lorenzo's MotoGP championship lead by winning at Indianapolis ahead of Ben Spies.
Lorenzo had to settle for third this time, followed by his Yamaha teammate Valentino Rossi and Pedrosa's Honda stablemate Andrea Dovizioso, but still heads the standings by 68 points.
Pedrosa's victory was ultimately a comfortable one, even though he was down in fourth behind shock polesitter Spies (Tech 3 Yamaha), fast-starter Dovizioso and Nicky Hayden's Ducati at the exit of the the first corner.
While Pedrosa picked off the fading Hayden and then Dovizioso, Spies settled in at the front of the field, establishing a one-second lead in the opening stages.
But Pedrosa was soon edging closer, and by lap six he was right on Spies' tail - drafting past with apparent ease on the pits straight and then pulling away. Spies stayed within a creditable distance though, and was never under any pressure from the works riders behind.
It took Lorenzo 11 laps to fight past Dovizioso to take third, and then longer still to shake the Honda off for good. Dovizioso later fell away from the pace, allowing Rossi to take fourth from him too.
Ducati had a very disappointing race. Hayden could not match his qualifying form and drifted back to sixth, while an unhappy Casey Stoner tumbled to ninth on lap one, recovered several positions, but then crashed out while chasing Rossi for fifth.
Marco Melandri was the first retirement, falling from eighth on lap two, but his Gresini Honda team-mate Marco Simoncelli had a strong run to seventh, closing on Hayden while fending off Alvaro Bautista's Suzuki and the Pramac Ducatis - of which only Aleix Espargaro reached the finish as Mika Kallio crashed once again.
Hector Barbera (Aspar Ducati) eventually beat Loris Capirossi's Suzuki to 10th in a fraught battle over resolved on the last lap.
Colin Edwards was the other retirement, parking his Tech 3 Yamaha due to extreme displeasure with his hard compound tires.
Pos Rider Team Time/Gap
1. Dani Pedrosa Honda 47m31.615s
2. Ben Spies Tech 3 Yamaha + 3.575s
3. Jorge Lorenzo Yamaha + 6.812s
4. Valentino Rossi Yamaha + 12.633s
5. Andrea Dovizioso Honda + 21.885s
6. Nicky Hayden Ducati + 35.138s
7. Marco Simoncelli Gresini Honda + 36.740s
8. Alvaro Bautista Suzuki + 36.825s
9. Aleix Espargaro Pramac Ducati + 44.905s
10. Hector Barbera Aspar Ducati + 51.368s
11. Loris Capirossi Suzuki + 55.386s
12. Hiroshi Aoyama Interwetten Honda + 57.903s
13. Randy de Puniet LCR Honda + 1m04.139s
Mika Kallio Pramac Ducati 18 laps
Colin Edwards Tech 3 Yamaha 16 laps
Casey Stoner Ducati 7 laps
Marco Melandri Gresini Honda 1 lap