A rain hit day one of the first official test in Sepang was dominated by the Petronas Yamaha duo of Fabio Quartararo and Franco Morbidelli.
The two men were the only riders able to break the 1:59.00 barrier with Alex Rins third for Suzuki.
The Petronas pair put together 91 laps combined with Quartararo doing 41 on of those. Morbidelli completed a half century of laps and finished 0.051s down to the Frenchman.
Before the test got underway Rins was a rider to follow closely, with Suzuki looking to make the extra step in 2020 in becoming a perennial championship threat.
The Spaniard had a productive day and also completed a half century of laps, while testing a new swingarm, chassis, electronics and more work on the engine.
Fourth fastest and the first Honda was Cal Crutchlow. The Brit completed 33 laps for the LCR team with Jack Miller 0.002s behind in fifth.
Miller has what many believe to be a chance of locking down a factory Ducati seat in 2021 with a big year, and the Australian made a good start with a solid run for the Pramac squad.
It wasn’t as easy a day for Mission Winnow Ducati riders Andrea Dovizioso and Danilo Petrucci who were both outside the top ten positions.
Sixth was Maverick Vinales for the Monster Energy Yamaha team, while Valentino Rossi finished day one in tenth place.
Both riders had two 2020 bikes at their disposal and also a 2019 model in order to test them back-to-back and gather more information.
Repsol Honda had a fairly quiet day with Marc Marquez completing 37 laps on his return from shoulder surgery.
Alex Marquez finished the day 0.242s behind his brother, as the pair closed out the day 12th and 13th.
Seventh and eighth were the Espargaro brothers with Aleix ahead of Pol. KTM and the Tech 3 team worked on the new chassis as Dani Pedrosa, Brad Binder and Iker Lecuona were all in action.
Pol told the media that more work and information was needed on the new ‘swingarm’ that they tried in what was a packed program for the Austrian team.