The green lights went on to signal the start of the second official MotoGP test of the year at 10am local time at the Sepang International Circuit in Malaysia.
The weather is typically hot and sunny, but has also been unpredictable of late - with even more afternoon rainstorms than usual.
As such, it is perhaps not a surprise that some bikes took to the track as soon as the session began, with Ducati's Valentino Rossi first to complete a lap.
All twelve manufacturer riders are again present for the three-day test, plus the Forward Racing and BQR 'Claiming Rule Teams'.
Repsol Honda's reigning world champion Casey Stoner was fastest at the first Sepang test earlier this month, setting a 1m 59.607s to finish 0.591sec ahead of Yamaha's Jorge Lorenzo.
Dani Pedrosa (Honda) was third, Ben Spies (Yamaha) fourth and Rossi fifth.