Singapore runner Shanti Pereira clocked a new national record in the women's 200m heats on Wednesday morning with a time of 24.12 seconds.
The 17-year-old lowered Dipna Lim-Prasad's national mark of 24.36sec - set in October this year - and was the second fastest qualifier.
Compatriot Tyra Summer Ree missed out on a place in the final after coming in last in the heats.
Shanti finished behind Vu Thi Huong of Vietnam, who clocked 23.99sec. Vu, 27, won the women's 100m on Tuesday and is heavily expected to snare the 200m crown as well.
The women's 200m final takes place later on Wednesday.