Following Sunday's season-ending Valencia Grand Prix, a two-day post season MotoGP test began at the circuit on Tuesday.
Day one was marred by poor weather, which caused seven of the 21 riders to remain in the pits and prompted the Factory Yamaha team to send Valentino Rossi and Jorge Lorenzo to Aragon for day two.
Unfortunately, it rained at both Valencia and Aragon on Wednesday morning - but conditions at Valencia finally improved enough for slick-tyre runs from mid-afternoon.
That convinced 2012 title runner-up Dani Pedrosa to head out for the first time since winning Sunday's race - and Pedrosa was on top of the timesheets by 3:30pm, when new Repsol Honda team-mate Marc Marquez finally made his MotoGP debut.
The Moto2 champion got to within 2.1s of Pedrosa at the end of his first run, but late-afternoon laps times are continuing to tumble as the track improves and Pedrosa is now over one-second clear of the field - and under the race lap record.
Marquez's fellow MotoGP rookie Bradley Smith made his own debut, on wet tyres, shortly after midday. Smith has since gone back out on slicks, while team-mate Cal Crutchlow is up to second place after being among those to sit out the wet weather.
Ben Spies, moving from Yamaha to Ducati for 2013, is not present due to recent surgery. His place is being taken by new Ducati test rider Michele Pirro.
Alvaro Bautista's Tuesday time was set on slicks, just before rain arrived.
Despite the poor weather, Rossi - who rode 28 wet laps during his Yamaha return at Valencia on Tuesday - and reigning champion Lorenzo have both reportedly been on track at Aragon, where some World Superbike teams are also testing.
Lorenzo fell without harm on the wet track.CLICK HERE
for extensive picture coverage from the Valencia MotoGP test...
1. Dani Pedrosa
ESP Repsol Honda (RC213V) 1m 32.481s
2. Cal Crutchlow
GBR Yamaha Tech 3 (YZR-M1) 1m 33.609s
3. Nicky Hayden
USA Ducati Team (GP12) 1m 33.623s
4. Stefan Bradl
GER LCR Honda MotoGP (RC213V) 1m 33.828s
5. Alvaro Bautista
ESP Honda Gresini (RC213V) 1m 33.994s
6. Andrea Dovizioso
ITA Ducati Team (GP12) 1m 34.453s
7. Michele Pirro
ITA Pramac Racing (GP12) 1m 34.573s
8. Randy De Puniet
FRA Aspar (ART CRT) 1m 34.758s
9. Marc Marquez
ESP Repsol Honda (RC213V) 1m 35.201s
10. Karel Abraham
CZE Cardion AB (ART CRT) 1m 35.578s
11. Andrea Iannone
ITA Pramac Racing (GP12) 1m 35.667s
12. Bradley Smith
GBR Yamaha Tech 3 (YZR-M1) 1m 35.775s
13. Danilo Petrucci
ITA IodaRacing (Suter-BMW CRT) 1m 35.904s
14. Hector Barbera
ESP Avintia (FTR-Kawasaki CRT) 1m 39.248s
15. Aleix Espargaro
ESP Aspar (ART CRT) 1m 43.517s
(35/40) Colin Edwards
USA Forward (FTR-Kawasaki CRT) No Time Hiroshi Aoyama
JPN Avintia (FTR-Kawasaki CRT) No Time Shane Byrne
GBR Paul Bird Motorsport (ART CRT) No Time Claudio Corti
ITA Forward (FTR-Kawasaki CRT) No Time Jorge Lorenzo
ESP Yamaha Factory (YZR-M1) Not present Valentino Rossi
ITA Yamaha Factory (YZR-M1) Not present Fastest Day 1 time:Alvaro Bautista
ESP Honda 1m 35.936sOfficial Valencia MotoGP records:Best lap: Dani Pedrosa
ESP Honda 1m 30.844s
(2012)Fastest race lap:Casey Stoner
AUS Ducati 1m 32.582s