Kraisart, riding an Yamaha, clocked one minute, 41.305 seconds around the 3.717-km track in the third free practice session late in the afternoon, bettering the previous best of 01:42.787 set by Kawasaki rider Azlan Shah Kamaruzaman of Malaysia, who is also the current championship leader.
The 600cc riders improved their timings through the three practice sessions before Kraisart led a bunch of nine who broke Kamaruzaman's record (01:42.785) set in 2013 when the event was last held at this venue.
Team RAMA Honda by NTS T.Pro Ten 10 rider Shankar Sarath Kumar, the lone Indian entrant in this class was about three seconds off the pace, but like others improved his timings through the day.
The other Indian, 18-year-old Rajiv Sethu of team RAMA Honda by NTS T.Pro Ten 10, taking part in the Asia Production 250cc class, was also off the pace, but improved his timing by nearly seven seconds over three practice sessions.
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Indian wild card entry in the Underbone 150cc class, Prabhu Arungagiri qualified 14th on the grid dominated by Malaysian riders.
Ranchi's Amit Richard Topno (Pro-Lap Racing), currently lying fifth in the championship, was quickest in the Honda CBR 250 category while leader Rajiv Sethu sat out the practice session.
Prabhu V topped the TVS Apache class ahead of Sivanesan S who has already clinched the title, and was the third quickest behind Anand Kumar S.