Overnight rain meant a damp track for the start of Thursday's final day of pre-season testing at Sepang in Malaysia.
The sun began to shine around the 10am track opening time and the circuit soon began to visibly dry.
Nevertheless, rather than wait for conditions to improve, many riders - including Jorge Lorenzo, Dani Pedrosa, Marc Marquez and Valentino Rossi
- took the opportunity to work on their wet set-ups.
By the close of the opening hour, ten riders had recorded a lap time, led by Lorenzo, who toppled Pedrosa from the head of the timesheets for the first time in 2013 yesterday.
Yamaha's reigning double MotoGP
champion set a 2m 13.130s, 13 seconds off dry pace, on the sixth of his 10 wet laps, with next best Pedrosa 0.437s behind for Repsol Honda.
Ducati's Nicky Hayden
moved into third (+0.667s) late in the first hour, pushing rookie Marc Marquez to fourth +1.910s and Valentino Rossi
to fifth (+1.951s).
Circuit television showed Marquez walking away after a fall from his RC213V at 10:40am. "Small crash in Turn 12 for Marc, touched the white line. Rider is ok," confirmed a subsequent Twitter message from HRC.
With the track becoming too dry for wet tyres, almost all riders had returned to the pits by 11am.