Spaniard Maverick Vinales claimed his first MotoGP win of the season in the Australian round at Phillip Island.
The 23-year-old, who was second in qualifying, crossed the line more than 1.5 seconds ahead of Andrea Iannone, with Andrea Dovizioso third.
Champion Marc Marquez began on pole but was forced to retire after a high-speed collision with Johann Zarco on lap six.
Meanwhile, Briton Cal Crutchlow has had surgery after breaking his ankle in Friday's second practice.
Crutchlow will be replaced by test rider Stefan Bradl at next weekend's Malaysian Grand Prix but remarkably targeted a return in the final race of the season in Valencia on 18 November.
LCR Honda's Oscar Haro said: "He wants to be in Valencia. He's thinking of riding there. You know how these guys are, especially Cal, he's a pitbull and he's very keen to get back because he wants to defend the Independent riders title. It was a hard fall and it's quite a complicated operation.
"He's broken the tibia, the malleolus. Surely, when they operate on him it will cause further injury to the ligaments and tendons and so we have to wait to see.
"I think it will be complicated for him to be in Valencia and we should be thinking about the Jerez test to test the new 2019 bike and think about 2019 because this year is now very complicated."
Spaniard Marquez, 25, sealed his fifth world title in Japan a week ago but now has the bizarre record now of failing to finish in Australia on three occasions after winning the world title in Asia.
He stayed on his bike after the collision with Zarco but his back seat was mangled and his suspension appeared damaged, forcing his first non-finish of the season.
However, he refused to blame the Frenchman, saying: "I feel very lucky. I will not complain because it was a racing incident."
1. Maverick Vinales (Spa/Yamaha) 40mins 51.081secs
2. Andrea Iannone (Ita/Suzuki) 40:52.624
3. Andrea Dovizioso (Ita/Ducati) 40:52.913
4. Alvaro Bautista (Spa/Ducati) 40:55.153
5. Alex Rins (Spa/Suzuki) 40:56.098
6. Valentino Rossi (Ita/Yamaha) 40:56.213
7. Jack Miller (Aus/Ducati) 40:57.837
8. Franco Morbidelli (Ita/Honda) 41:12.886
9. Aleix Espargaro (Spa/Aprilia) 41:13.985
10. Bradley Smith (GB/KTM) 41:14.021
1. Marc Marquez (Spa/Honda) 296 points
2. Andrea Dovizioso (Ita/Ducati) 210
3. Valentino Rossi (Ita/Yamaha) 195
4. Maverick Vinales (Spa/Yamaha) 180
5. Cal Crutchlow (GB/LCR Honda) 148
6. Danilo Petrucci (Ita/Ducati Pramac) 137
7. Johann Zarco (Fra/Yamaha Tech3) 133
8. Andrea Iannone (Ita/Suzuki) 133
9. Jorge Lorenzo (Spa/Ducati) 130
10. Alex Rins (Spa/Suzuki) 129