Casey Stoner extended his MotoGP championship lead with an eighth win of the season at Aragon in Spain.
The Australian took the lead at the end of the first lap and streaked away to comfortably beat Repsol Honda team-mate Dani Pedrosa.
Reigning champion Jorge Lorenzo was third ahead of Marco Simoncelli, with Ben Spies fifth.
Lorenzo is now 44 points adrift of Stoner in the standings with just four races left of the season.
Stoner is odds-on favourite to regain the title he last won on a Ducati in 2007.
British rider Cal Crutchlow was ninth on his Tech 3 Yamaha after a race-long duel with Valentino Rossi.
Stoner told BBC Sport: "We're pretty much back to our best.
"It felt good all weekend. The bike has been fantastic and the only problem was the wind - it was changing direction and speed every lap so that was a challenge but I just had to bring it home.
"It was my race to lose today and I did the job."
Rossi started from the pit lane in very windy conditions as Spies made a storming start to take the lead at turn one.
Pedrosa barged past Repsol Honda team-mate Stoner, but the Australian was soon into the lead at the end of the long straight.
Spies then ran wide to allow Pedrosa to pass him for second.
Third Repsol rider Andrea Dovizioso failed to last the first lap as he crashed out, before Simoncelli passed Lorenzo for fourth.
Stoner was able to open up a comfortable gap at the front while Lorenzo was handed fourth spot when Simoncelli overshot the turn at the end of the straight and had to take to the run-off area.
Simoncelli was able to rejoin in fifth while Rossi made his way gradually through the pack.
Lorenzo closed in on team-mate Spies and muscled past with 10 laps to go before Simoncelli was able to follow Lorenzo through and retake fourth spot.
Stoner eased to his 31st victory in the top class, putting him joint fifth on the all-time list, as he moved 44 points clear with just 100 points left to play for.
Lorenzo said: "It was impossible to win today so third is not too bad. Casey was just too fast."
There were wins for Spanish riders in both support races, as Marc Marquez took a thrilling Moto2 win to cut Stefan Bradl's championship lead to just six points, while Nicolas Terol won the 125cc race to extend his championship lead.
Aragon MotoGP result:
1. Casey Stoner (Aus) Repsol Honda 42'17.427
2. Dani Pedrosa (Spn) Repsol Honda 42'25.589
3. Jorge Lorenzo (Spn) Yamaha 42'31.636
4. Marco Simoncelli (Ita) Gresini Honda 42'38.073
5. Ben Spies (USA) Yamaha 42'45.166
6. Alvaro Bautista (Spn) Suzuki 42'47.800
7. Nicky Hayden (USA) Ducati 42'51.715
8. Hector Barbera (Spn) Aspar Ducati 42'54.732
9. Cal Crutchlow (GBR) Tech 3 Yamaha 42'57.079
10. Valentino Rossi (Ita) Ducati 42'57.424
Moto2 race result:
1. Marc Marquez (Spn) Suter 40'20.575
2. Andrea Iannone (Ita) Suter 40'23.041
3. Simone Corsi (Ita) FTR 40'23.149
4. Alex De Angelis (RSM) Motobi 40'23.629
5. Aleix Espargaro (Spn) Pons Kalex 40'31.406
6. Bradley Smith (GBR) Tech 3 40'31.445
125cc race result:
1. Nicolas Terol (Spn) Aprilia 40'26.726
2. Johann Zarco (Fra) Derbi 40'33.497
3. Maverick Vinales (Spa) Aprilia 40'45.655
4. Efren Vazquez (Spa) Derbi 40'54.198
5. Luis Salom (Spa) Aprilia 40'54.195
6. Danny Kent (GBR) Aprilia 40'54.476