Second Asean Schools Games (ASG), second gold medal, second time breaking the Games record.
Thailand pole vaulter Suttikan Khammun proved her credentials ahead of the SEA Games when she cleared 3.5 metres to smash her 3.41m Games record set when she won in Chiang Mai last year.
The 18-year-old was delighted after her emphatic win at the Bishan Stadium yesterday, saying: "I feel happy and proud to stand in the podium and hear my anthem being played in another country.
"I had a lot of headaches and I fell sick many times before this tournament, but it doesn't matter now that I won."
Malaysia's Puteri Nur Adillah Shik Azizir Rahman came in second on 3.4m and Diva Renatta Jayadi of Indonesia was third on 3.20m.
Suttikan led the charge in Thailand's medal hunt as the Thais won five golds, three silvers and three bronzes out of 12 events on the first day of the athletics competition.
They swept the blue-riband 100m sprint events, with Siripol Punpa winning the boys' event in 10.79sec, and Jintana Phuettonglang clinching the girls' 100m gold in 12.40sec.
Thailand won the most medals at last year's Games, stacking up 56 golds, 36 silvers and 33 bronzes.
Singapore also saw gold at Bishan yesterday, as reigning Schools National B Division girls' discus champion Jasmin Phua prevented a Thai podium sweep by winning with a 40.77m effort, eclipsing her previous personal-best of 37.07m.
Thanapha Sriyongyos came in second with 39.43m, while her compatriot Athima Saowaphaiboon clinched bronze with 33.59m.
Jasmin, 16, won a bronze at last year's ASG and was looking to improve on her performance.
The Nanyang Girls' High School (NYGH) student said: "Today, I wasn't expecting any medal, but I was expecting a personal best.
"I fixed a lot of technical issues (coming into this competition), so I expected improvement. But I was very surprised (to win the gold)."
She will be gunning for another medal in the shot put event tomorrow.
In April, she set a new Schools National B Division shot put record, with her 12.73m effort eclipsing Jocelyn Yeo's 11-year-old mark of 12.66m. Jasmin is also looking forward to qualifying for next year's Youth Olympic Games.
Eric Yee was the other Singaporean to clinch a medal yesterday, bagging a silver in the boys' discus with a throw of 52.60m.
The 18-year-old finished behind Thongchai Sialmool of Thailand, who took the gold with 55.39m.