France's Johann Zarco was quickest in unexpectedly dry conditions for the opening practice sessions at the Thai MotoGP on Friday, pipping world championship title contender Francesco Bagnaia.
Riders had one eye on the overcast sky and forecast storms over the international circuit at Buriram, about 400 kilometres (250 miles) from Bangkok.
But the rain stayed away for both practice sessions as Zarco -- a Ducati rider seeking his first MotoGP win -- clocked a leading time of one minute and 30.281 seconds in the afternoon.
"I'm pretty happy with this afternoon," Zarco said, adding he hopes for a dry track on Saturday for qualifying -- heavy rain and thunderstorms are forecast.
"Still not 100 percent comfortable on the brake and we must improve this area to be ready for the race."
Ducati dominated as Italian Bagnaia, who is trailing world champion Fabio Quartararo by 18 points in the standings with four races left, was second-fastest. He was just 0.018sec off Zarco.
Spain's Jorge Martin was third.
Six-time MotoGP world champion Marc Marquez, who is working his way back to full fitness after surgery, was fourth-fastest across both sessions.
Under-pressure Quartararo of France, who has seen his championship lead whittled away by Bagnaia in the second half of the season, came fifth on his Yamaha.
"With the bike, I didn't find a good feeling today... the lap times are good, but I'm not comfortable on the bike," Quartararo told reporters.
The third of the serious title contenders, Aleix Espargaro from Spain, finished outside the top 10 for Aprilia along with Italy's Enea Bastianini.
MotoGP is returning to Thailand for the first time since 2019 because of coronavirus disruptions.