Chantal Liew won a SEA Games bronze in a personal-best 2hr 21min 30sec in the 10km open water swim and became the first Singapore woman to win a medal in the event.
"It feels amazing to have been able to contribute towards Singapore's medal tally and I'm so grateful to (record a) PB (personal best)," she said, after only the fifth race of her career.
For Liew, the best part was racing against Malaysia's two-time Olympian, Heidi Gan, who won the gold medal yesterday.
"It's such a huge honour, she's almost 10 years older than me and I have so much to learn from her," said the 19-year-old.
"Same with (silver medallist) Benjaporn (Sriphanomthorn). She was a medallist at the Asian Championships so the best part was racing and learning from them."
Gan, 28, posted 2:11:02 at Putrajaya's Water Sports Complex to win by a massive distance from Benjaporn, who clocked 2:16:37.
Liew thought she was a "goner" in the second round, as trying to keep up with Gan, Benjaporn and Yessy Venesia Yosaputra in the first round took a toll on her. There were six rounds in the race.
"I was talking to my coaches and there was a huge time difference between my first and second round.
"By the third round, I think the Indonesian girl had pulled away from me by a minute and I thought I was gone," she said. "I just tried to swim buoy to buoy and focus on one thing at a time, try to swim my own race and hope for the best."
Yesterday was not the first time Liew and Yosaputra had raced against each other. At the 2015 SEA Games in Singapore, both women swam in the 200m backstroke and Yosaputra was second while Liew finished eighth.
Liew added: "It was nice to get some revenge."
Singapore's other representative in the women's 10km race, Chin Kar Yi, was sixth among the nine swimmers, finishing in a personal-best 2:33:03.
In the men's event, Benedict Boon was fifth out of nine swimmers in 2:12:24 while team-mate Erasmus Ang was seventh in 2:13:18. The top three spots were occupied by Malaysia's Kevin Yeap (2:03:18), Thailand's Peerapat Lertsathapornsuk (2:05:41) and Indonesia's Aflah Fadlan Prawira (2:08:40).
Open water swimming was last held at the 2011 SEA Games in Palembang, where Singapore also won a bronze through Boon's older brother Brandon.