Jorge Lorenzo's MotoGP world title hopes remain alive after he won a dramatic Australian Grand Prix which saw championship leader Marc Marquez disqualified.
Yamaha's Lorenzo, who started from pole and led throughout, now trails his fellow Spaniard by 18 points going into next week's penultimate race in Japan.
Riders had to change bikes mid-race because of safety concerns over tyres.
But Marquez failed to pit by the required time and scored no points.
After the race, BBC Sport's MotoGP presenter Matt Roberts tweeted that Marquez's Honda team had said it was a pit-board error which led to their rider being disqualified.
Dani Pedrosa was second while Valentino Rossi held off the challenge of Britain's Cal Crutchlow for third.
Lorenzo described the race as "crazy" because of the compulsory bike change but his maximum return of 25 points, coupled with Marquez failing to register, means the title race has been opened up.
"We were lucky," said Lorenzo. "Without the mistake from Marc I think he would have been first or second - now the championship has changed so much.
"Before the race we had no chance - a 2% or 3% chance - and now it's 20% or 30%.
"Let's see what happens in Motegi." [the venue for next Sunday's race in Japan]
After setting the fastest time in qualifying, Lorenzo started well from pole and held off Marquez and Pedrosa in the opening lap before looking very comfortable.
Tyre supplier Bridgestone said before the race that they were unable to guarantee the safety of their rear slick tyres beyond 10 laps because of the newly-resurfaced track at Phillip Island.
As a result, it was decided to shorten the race to 19 laps from 27, with a mid-race pit stop.
Pedrosa was the first of the top three to pit on lap nine, while Lorenzo made his change on the following lap.
However, Marquez stayed out on the track until lap 11 and when he rejoined the race he had a minor clash with Lorenzo for top spot but the race leader retained his advantage.
Marquez's hopes of securing the title in his rookie season then suffered a blow when he was shown the black flag for exceeding the maximum number of laps permitted before having to pit.
1. Jorge Lorenzo (Spain) Yamaha 29 minutes 07.155 seconds
2. Dani Pedrosa (Spain) Honda +6.936 secs
3. Valentino Rossi (Italy) Yamaha +12.344
4. Cal Crutchlow (Britain) Yamaha +12.460
5. Alvaro Bautista (Spain) Honda +12.513
6. Bradley Smith (Britain) Yamaha +28.263
7. Nicky Hayden (US) Ducati +32.953
8. Andrea Iannone (Italy) Ducati +35.062
9. Andrea Dovizioso (Italy) Ducati +35.104
10. Randy de Puniet (France) Aprilia +37.426
1. Marc Marquez (Spain) Honda 298 points
2. Jorge Lorenzo (Spain) Yamaha 280
3. Dani Pedrosa (Spain) Honda 264
4. Valentino Rossi (Italy) Yamaha 214
5. Cal Crutchlow (Great Britain) Yamaha 179