Jonathan Rea posted a first session lap time under the existing race lap record and then improved it again in the afternoon to lead the field in the first contact with the Chang International Circuit this season.
His best lap was eventually a 1’33.573, compared to the race lap record of 1’33.817.
Given the rise in track and air temperatures in the afternoon session, Rea did not improve his morning session time until right at the end, but most top runners also eventually went marginally faster than their morning times.
2016 season Thai race winner Tom Sykes looked like he was about to pull one of his super-special laps out of the hat but he finally finished second, 0.210 from his team-mate Rea.
After the first look at the 4.554km long track in his career Marco Melandri was third fastest, with Chaz Davies close behind
Alex Lowes made a positive start at a circuit he has podiumed at in the past, when riding for different manufacturers, going fifth overall today.
Xavi Fores took his privateer Ducati sixth and Jordi Torres was seventh.
Michael van der Mark slotted in eighth and the second BMW rider in the field, Markus Reiterberger went ninth fastest.
Eugene Laverty eventually made it into the top ten, one place ahead of his team-mate Lorenzo Savadori after a tough morning session.
The first of the new Fireblade riders was Stefan Bradl, 12th with his team-mate Nicky Hayden 13th. Hayden was 1.376 seconds from the fastest after one day.
Leon Camier made it up to 14th after setting no laps in the morning session, thanks to a technical issue.
Randy Krummenacher was 15th.
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