Andrea Dovizioso topped the opening practice session for MotoGP's Malaysian Grand Prix, leading Alvaro Bautista and Johann Zarco in mostly dry conditions.
Ducati rider Dovizioso took top spot right at the end, his 2m00.671s lap good enough to knock Aspar Ducati's Bautista down to second.
Points leader Marc Marquez was fifth quickest, while Valentino Rossi and Andrea Iannone failed to make the most of the dry running to bank a top-10 spot for qualifying.
A downpour minutes before the beginning of the session meant there was little meaningful running in the first 25 minutes. Bautista and Jack Miller enjoyed spells at the top, the times languishing back in the 2m05s as crews began running on slick tyres.
With 15 minutes to go the big names joined the party, Marquez leaping to the top with a 2m03.472s.
He was immediately replaced by Zarco's 2m02.841s, before Marquez fired back with a 2m01.232s, then a 2m00.950s with just under four minutes to go.
It wasn't until the chequered flag that Marquez was joined in the 2m00s - Bautista initially taking top spot with a 2m00.742s.
He was then knocked back by Dovizioso's late effort, while Zarco slotted into third with a 2m00.807s.
Maverick Vinales improved at the flag to go fourth quickest on a 2m00.903s, which demoted Marquez to fifth.
Cal Crutchlow was sixth, Karel Abraham seventh, and Hector Barbera eighth.
Dani Pedrosa, who struggled with a clutch problem, was ninth, with Jorge Lorenzo rounding out the top 10.
With the weather expected to be fickle throughout the weekend, Rossi will need at least another dry practice session if he's to make it directly into Q2.
The Yamaha rider was only 12th quickest, sandwiched between Danilo Petrucci and Andrea Iannone.
Michael van der Mark, standing in as a replacement for the ill Jonas Folger at Tech3 Yamaha, was 19th quickest, 2.8s off Dovizioso's time.
|2||Alvaro Bautista||Aspar Ducati||Ducati||2m00.742s||0.071s||17|
|3||Johann Zarco||Tech3 Yamaha||Yamaha||2m00.807s||0.136s||14|
|6||Cal Crutchlow||LCR Honda||Honda||2m01.060s||0.389s||15|
|7||Karel Abraham||Aspar Ducati||Ducati||2m01.077s||0.406s||11|
|8||Hector Barbera||Avintia Ducati||Ducati||2m01.147s||0.476s||15|
|11||Danilo Petrucci||Pramac Ducati||Ducati||2m01.560s||0.889s||9|
|14||Jack Miller||MVDS Honda||Honda||2m01.803s||1.132s||14|
|16||Loris Baz||Avintia Ducati||Ducati||2m02.416s||1.745s||10|
|18||Scott Redding||Pramac Ducati||Ducati||2m03.056s||2.385s||11|
|19||Michael van der Mark||Tech3 Yamaha||Yamaha||2m03.473s||2.802s||11|
|20||Tito Rabat||MVDS Honda||Honda||2m03.531s||2.860s||13|