Jorge Lorenzo staged a late surge to win a superb opening race of the MotoGP season in Qatar.
Lorenzo looked set for second behind defending champion Casey Stoner for most of the race but took control with three laps left and won the night race by 0.852 seconds ahead of Dani Pedrosa.
Stoner suffered from arm pump in the closing stages as he came home third.
British rider Cal Crutchlow was fourth, while seven-time champion Valentino Rossi was only 10th on his Ducati.
Lorenzo started the first race of the 1,000cc era on pole and led into the first corner, with Pedrosa making a stunning start to take second from his seventh place on the grid.
Crutchlow - starting from a career-best third on the grid - went backwards from the start and found himself in seventh place.
Stoner moved past Repsol Honda team-mate Pedrosa into second at the end of lap two, and took the lead over the finish line a lap later.
Australian Stoner - - then opened up a near two-second lead and looked likely to win in Qatar for the fifth time in the last six years.
But, with five laps remaining, Stoner's pace began to drop as he struggled with arm pump - when the huge braking forces required to stop from 210mph cause muscle spasms in a rider's forearm - and Lorenzo and Pedrosa were both able to pass the champion.
Crutchlow had time to win his race-long battle with team-mate Andrea Dovizioso to pass the Italian and match his best-ever finish of fourth.
The Briton told BBC Sport: "We've all worked hard over the winter and we've proved a lot of people wrong.
"Andrea was third in the championship last year so he's no slouch, so it was great to beat him. We didn't get the podium this time but it's not far away."
Stoner believes that he would have held on for victory if it was not for his arm troubles in the closing stages.
He said: "We were by far the fastest out there but, after four laps, I started to get real arm pump, my arms were shaking off the bars and I was holding on with two fingers.
"I couldn't grip and I couldn't use the brakes. Without that there was no problem to win, we're really happy with the speed of the bike.
"I've got two weeks to go away and train and we can come back again."
Earlier, Marc Marquez won a thrilling Moto2 race ahead of Andrea Iannone on the line, with Scott Redding the top Brit in sixth place.
In the first ever race in the Moto3 class - which replaces the 125cc class this season - 17-year-old Maverick Vinales took the win ahead of Romano Fenati.
British rider Danny Kent was eighth.
Qatar MotoGP selected results:
1. Jorge Lorenzo (SPA) Yamaha 42:44.124
2. Dani Pedrosa (SPA) Repsol Honda 42:45.066
3. Casey Stoner (AUS) Repsol Honda 42:47.122
4. Cal Crutchlow (GBR) Tech 3 Yamaha 43:01.328
5. Andrea Dovizioso (ITA) Tech 3 Yamaha 43:01.634
6. Nicky Hayden (USA) Ducati 43:12.627
7. Alvaro Bautista (SPA) Gresini Honda 43:12.660
8. Stefan Bradl (GER) LCR Honda 43:13.678
9. Hector Barbera (SPA) Pramac Ducati 43:15.598
10. Valentino Rossi (ITA) Ducati 43:17.879