Jorge Lorenzo came out on top of a battle with fellow Yamaha men Cal Crutchlow and Valentino Rossi to head the first practice session of the 2013 MotoGP season in Qatar.
Rossi had looked set to announce his return to Yamaha with a superb fastest time of the evening for much of the session.
He set the early pace with a 1m57.256s, and though Lorenzo deposed him mid-session, it was mere seconds until Rossi was back in front.
A further improvement with 13 minutes to go took Rossi three tenths clear, before Tech 3 rider Crutchlow slipped ahead going into the last five minutes.
Both were to be upstaged by Lorenzo. Two 1m56.6s laps from the world champion gave him first place by 0.058s over Crutchlow and 0.071s over Rossi.
Marc Marquez was the leading Honda in fourth, half a second down.
His factory team-mate Dani Pedrosa was four places further back and slowest of the Hondas as he struggled with the handling on corner entry.
Andrea Dovizioso gave Ducati early encouragement with fifth position, achieved despite sticking to hard tyres - unlike all those ahead.
Aleix Espargaro surged to the fastest CRT time in ninth overall, ahead of Nicky Hayden's factory Ducati prototype and nearly 2s clear of his peers.
The dubious honour of the season's first crash went to Yonny Hernandez.
The Colombian lost the front of Paul Bird's Aprilia into Turn 12 just 10 minutes in.
But Hernandez was far from the only man to make a mistake in the very dusty conditions.
Pedrosa, Stefan Bradl, Bradley Smith, Andrea Iannone and Espargaro all slithered over run-off areas or gravel traps, in some cases several times.
Pos Rider Team/Bike Time Gap 1. Jorge Lorenzo Yamaha 1m56.685s 2. Cal Crutchlow Tech 3 Yamaha 1m56.743s + 0.058s 3. Valentino Rossi Yamaha 1m56.756s + 0.071s 4. Marc Marquez Honda 1m57.276s + 0.591s 5. Andrea Dovizioso Ducati 1m57.538s + 0.853s 6. Alvaro Bautista Gresini Honda 1m57.601s + 0.916s 7. Stefan Bradl LCR Honda 1m57.670s + 0.985s 8. Dani Pedrosa Honda 1m57.749s + 1.064s 9. Aleix Espargaro Aspar Aprilia 1m57.843s + 1.158s 10. Nicky Hayden Ducati 1m57.926s + 1.241s 11. Bradley Smith Tech 3 Yamaha 1m58.369s + 1.684s 12. Andrea Iannone Pramac Ducati 1m58.559s + 1.874s 13. Ben Spies Pramac Ducati 1m58.575s + 1.890s 14. Hector Barbera Avintia FTR-Kawasaki 1m59.608s + 2.923s 15. Randy de Puniet Aspar Aprilia 1m59.633s + 2.948s 16. Karel Abraham Cardion Aprilia 1m59.758s + 3.073s 17. Colin Edwards Forward FTR-Kawasaki 2m00.341s + 3.656s 18. Yonny Hernandez PBM Aprilia 2m00.426s + 3.741s 19. Hiroshi Aoyama Avintia FTR-Kawasaki 2m00.563s + 3.878s 20. Claudio Corti Forward FTR-Kawasaki 2m01.227s + 4.542s 21. Danilo Petrucci Ioda-Suter-BMW 2m01.438s + 4.753s 22. Bryan Staring Gresini FTR-Honda 2m01.942s + 5.257s 23. Lukas Pesek Ioda-Suter-BMW 2m02.079s + 5.394s 24. Michael Laverty PBM-Aprilia 2m02.135s + 5.450s