2013 MotoGP action got underway with the start of the first official test, attended by all teams and riders, at Sepang in Malaysia on Tuesday.

After a special test exclusively for privateer 'CRT' entries using the standard ECU, marred by bad weather and technical gremlins, the threat of rain meant riders wasted no time at the start of the main three-day test.

Conditions were cloudy throughout, but the rain stayed away and Tuesday thus marked the first dry laps for Valentino Rossi since his Yamaha return.

Ben Spies rode his first laps for Pramac Ducati - but finished early due to his healing shoulder - while Michael Laverty (PBM) and Bryan Starling (Gresini) made their MotoGP debuts.

Marc Marquez and Alvaro Bautista took part in a private Honda test at Sepang last November.

Testing, which began at 10am, will restart on Wednesday morning.

CLICK HERE for pictures from the test...

1.Dani Pedrosa ESP Repsol Honda (RC213V)2m 1.157s(Lap 48/49)

2.Jorge Lorenzo ESP Yamaha Factory (YZR-M1)2m 1.165s(57/58)

3.Marc Marquez ESP Repsol Honda (RC213V)2m 1.201s(60/62)

4.Valentino Rossi ITA Yamaha Factory (YZR-M1)2m 1.584s(30/56)

5.Stefan Bradl GER LCR Honda MotoGP (RC213V)2m 1.789s(43/59)

6.Cal Crutchlow GBR Yamaha Tech 3 (YZR-M1)2m 1.881s(46/64)

7.Alvaro Bautista ESP Honda Gresini (RC213V)2m 1.981s(52/59)

8.Katsayuki Nakasuga JPN Yamaha Test Rider (YZR-M1)2m 2.968s(50/58)

9.Kosuke Akiyoshi JPN Honda Test Rider (RC213V)2m 2.972s(46/69)

10.Nicky Hayden USA Ducati Team (GP13)2m 3.336s(22/62)

11.Wataru Yoshikawa JPN Yamaha Test Rider (YZR-M1)2m 3.456s(14/46)

12.Bradley Smith GBR Yamaha Tech 3 (YZR-M1)2m 3.460s(53/56)

13.Andrea Dovizioso ITA Ducati Team (GP13)2m 3.535s(35/48)

14.Aleix Espargaro ESP Aspar (ART CRT)2m 3.782s(54/58)

15.Randy De PunietFRA Aspar (ART CRT)2m 4.283s(42/56)

16.Andrea Iannone ITA Pramac Racing (GP13)2m 4.500s(53/57)

17.Ben Spies USA Pramac Racing (GP13)2m 5.086s(19/21)

18.Takumi Takahashi JPN Honda Test Rider (RC213V)2m 5.154s(68/70)

19.Hector Barbera ESP Avintia (FTR-Kawasaki CRT)*2m 5.469s(37/41)

20.Yonny Hernandez COL Paul Bird Motorsport (ART CRT)2m 5.656s(39/50)

21.Karel Abraham CZE Cardion AB (ART CRT)2m 5.694s(30/54)

22.Danilo Petrucci ITA IodaRacing (Suter-BMW CRT)*2m 5.753s(27/29)

23.Hiroshi Aoyama JPN Avintia (FTR-Kawasaki CRT)*2m 5.919s(47/48)

24.Claudio Corti ITA Forward (FTR-Kawasaki CRT)*2m 6.426s(29/38)

25.Michael Laverty GBR Paul Bird Motorsport (ART CRT)2m 6.507s(42/43)

26.Lukas Pesek CZE IodaRacing (Suter-BMW CRT)*2m 7.015s(40/46)

27.Bryan Staring AUS Honda Gresini (FTR-Honda CRT)2m 7.044s(33/41)

28.Colin Edwards USA Forward (FTR-Kawasaki CRT)*2m 8.206s(24/25)

* Control ECU.

Official Sepang MotoGP records: Best lap: Jorge Lorenzo ESP Yamaha 2m 0.334s (2012)Fastest race lap:Casey Stoner AUS Ducati 2m 2.108s (2007)

Fastest lap in 2012 pre-season testing: Casey Stoner AUS Honda 1m 59.607s (February 2)

Fastest lap in private Honda Sepang test: Marc Marquez ESP Repsol Honda 2m 1.355s (November 27)