Casey Stoner extended his lead at the top of the MotoGP standings with a comfortable win in the Czech Republic.
Stoner was handed the lead when his Repsol Honda team-mate Dani Pedrosa crashed out on lap four.
And the Australian took full advantage to power away and beat third Repsol rider Andrea Dovizioso by 6.5 seconds.
Reigning champion Jorge Lorenzo struggled throughout with a soft tyre and was only fourth as Stoner moved 32 points clear in the championship.
Marco Simoncelli finally claimed his first podium finish with third place, while Valentino Rossi showed some improvement on his way to sixth.
It was another bad day for British rider Cal Crutchlow as he again crashed out on his Tech 3 Yamaha.
Stoner told BBC Sport: "We knew we could be on the podium but it looked tough for the win so I'm delighted.
"I had a good early battle with Andrea and I thought Dani would get away but the bike felt good. Then Dani crashed out and I tried to pull a gap by putting in some real quick laps and then it was all about managing it to the finish."
Simoncelli has twice taken pole position this season but has been guilty of crashing far too often.
But the Italian put in a mature ride to come home in third spot.
He told BBC Sport: "I have waited a long time for this result. I am really, really happy.
"I have had a lot of difficult moments but I never stopped believing."
Pedrosa made a trademark flying start but Lorenzo dived into the lead at turn three to head the three Repsol Hondas.
Lorenzo managed a miraculous escape on the third lap when he lost the front end but managed to keep the bike upright by digging his knee into the tarmac.
Pedrosa took advantage to take the lead but lasted just a few corners before he crashed out as Stoner inherited first place.
Crutchlow dropped out with 16 laps to go as he crashed at turn one, failing to register any points for the fifth time in the last eight races.
Dovizioso and Simoncelli both passed reigning champion Lorenzo in half a lap as his front tyre lost grip. Stoner survived one scary moment when he clipped the kerb at turn one but had enough of a lead to ease off and cruise home for his 29th MotoGP win.
1. Casey Stoner (Aus) Repsol Honda 43'16.796
2. Andrea Dovizioso (It) Repsol Honda 43'23.328
3. Marco Simoncelli (It) Gresini Honda 43'24.588
4. Jorge Lorenzo (Spn) Yamaha 43'25.309
5. Ben Spies (USA) Yamaha 43'26.982
6. Valentino Rossi (It) Ducati 43'29.428
7. Nicky Hayden (USA) Ducati 43'39.833
8. Colin Edwards (USA) Tech 3 Yamaha 43'40.985
9. Hiroshi Aoyama (Jpn) Gresini Honda 43'41.998
10. Hector Barbera (Spn) Aspar Ducati 43'53.362
Moto2 race result:
1. Andrea Iannone (Ita) Suter 41'13.255
2. Marc Marquez (Spn) Suter 41'13.416
3. Stefan Bradl (Ger) 41'13.662
125cc race result:
1. Sandro Cortese (Ger) Aprilia 40'59.229
2. Johann Zarco (Fr) Derbi 40'59.626
3. Alberto Moncayo (Spn) Aprilia 41'10.002