Taekwondo martial artist Nguyen Thanh Thao won silver in the girls' 55kg category at the first Youth Olympic Games in Singapore, losing to Briton Jones Jade on Tuesday.
The 17-year-old martial artist from Wales led three to one after the first round of the final contest, but Thao, also 17, fought back to draw level after the second round.
Jones led 6-4 early in the third round but Thao restored parity again at 6-6 before the end of the round.
In the sudden-death play-off, Jones landed a kick to Thao's head to get three points and win Britain's first gold medal at the August 14-26 event.
Earlier, weightlifter Thach Kim Tuan snatched the gold medal in the men's 56kg category and taekwondo martial artist Nguyen Quoc Cuong grabbed the bronze medal in the men's 55kg competition.
After three days, China leads the Youth Olympics with a medal haul of five golds, three silvers and one bronze, followed by Azerbaijan with five golds and one silver medal. In third place is Russia with four gold, four silver and three bronze medals.
Italy is in fourth place with three gold, three silver and one bronze medal, while South Korea has the fifth spot with three gold, one silver and one bronze.
Vietnam is in 14th place with one gold, one silver and one bronze medal.