Marc Marquez led a Repsol Honda 1-2 at the end of the second day of MotoGP testing at the Buriram Circuit in Thailand.
Honda has hit the ground running at the second pre-season test of the year, with factory-backed LCR rider Cal Crutchlow fastest of the pack after Friday's running.
Marquez – who turns 25 years old today (Saturday) – was the early pacesetter on his RC213V with a 1:30.292s.
Both Marquez and team-mate Dani Pedrosa continued to work on their latest engine as well as an updated aerodynamic fairing.
Pedrosa took over at the top of the timesheets in the afternoon with a 1:30.127s, but was deposed in the closing 20 minutes of the session by Marquez, who set the first ever sub-1:30s lap of the Buriram track with a 1:29.969s.
With the field using the final 10 minutes for practice starts, the Honda rider remained unchallenged when the chequered flag flew. Pedrosa held onto second spot ahead of Jack Miller, who continues to look a strong competitive force on his Pramac Ducati GP17.
Yamaha endured a tough opening day, with Valentino Rossi struggling under acceleration, while team-mate Maverick Vinales was left baffled by a lack of edge grip and a loss of bike balance.
Languishing outside of the top 10 for much of the day, a late 1:30.274s put Vinales up to fourth. Rossi, who focused on his M1's electronics on Saturday, was 14th at the end of the session.
Tech3's Johann Zarco completed the top five ahead of Danilo Petrucci on the second Pramac bike and Suzuki's Alex Rins, who suffered a fast crash earlier in the day while testing a new aero fairing.
Friday pacesetter Crutchlow headed the factory Ducati duo of Andrea Dovizioso and Jorge Lorenzo – who continued to their work on three different fairings, with Dovizioso running a new frame – to round out the top 10. Andrea Iannone was 11th after a tumble at Turn 6.
LCR's Takaaki Nakagami was once again top rookie in Thailand, the Japanese rider shaving almost seven tenths off of his Friday best to end the session 15th and just nine tenths off the pace.
Hafizh Syahrin found over a second on Saturday to post a 1:31.998s on Saturday, putting the Tech3 rookie into 23rd, ahead of Xavier Simeon – who crashed at the last corner at the start of the session – and just 0.004s behind Tom Luthi.
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