Forbes placed decent third in the 100-m hurdles in 15.5 seconds to gain the finals where she will challenge two runners from China and Japan, India, Thailand, Malaysia and Singapore.
Running on lane 2, Forbes, a veteran of five international athletic competitions and competing for the second time in the meet since 1998 also held in Bangkok, cleared the last of 10 hurdles well ahead of local bet Pattraprom Promari, who finished 15.31 seconds.
Fangqian Ji of China topped the event in 13.76 seconds, beating Fumiko Kumagai of Japan, who came in second in 14.25 seconds.
Few minutes after placing third in the 100-m hurdles, Forbes returned to the oval of Thammasat Sports Complex and erased from the record book the 1:02.81 she set last May with a new mark 1:02.37.
Her record-breaking performance, however, was good only for fifth behind Hongfan Xiao of China, who won the gold in 59.28 seconds. The Chinese runner beat Galina Pedan of Kyrghyztan, who took the silver in 1:00.52. Chiea Nishio of Japan got the bronze in 1:00.66.
"I’m happy for her because she broke her own national junior record. She made considerable improvement in the 400-m hurdles," said Patafa president Go Teng Kok.