Indonesian riders led all free practice sessions in Asia Production 250cc by margins that left the rest wondering how to respond.

Astra Honda’s Mario Suryo Aji set the fastest time of the day just 8 laps into the first session, recording 1:42.310, which is half a second better than Gerry Salim managed on his way to pole position in 2017 and 0.8s better than championship leader, Rheza Danica Ahrens, managed in the early run-out.

Home advantage aside, there was more evidence of the depth of the new generation of fast Indonesians, as Yamaha riders, M. Faerozi and Rafid Topan Sucipto also dipped under 1:43 to top the second and third sessions, while Manual Tech KYT Kawasaki’s Andy Fadly managed a best time of 1:43.074. The best of the visitors was Yamaha Thailand’s Anuparb Sarmoon, who lies third in the championship. He clocked his best time of 1:43.549 on his fourth flying lap of the day, but spent the rest of the day in the 1:44s. AP Honda’s Muklada Sarapuech, who makes a return after the nasty hand injury she sustained at Suzuka, was a few hundredths adrift of her compatriot and two tenths clear of team-mate, Kritchaporn Kaewsonthi, who improved through the day to record 1:44.702 in the final session.