Female swimmer Nguyen Thi Anh Vien and female long jumper Nguyen Thi Truc Mai, both 16, won gold medals at the Asian Youth Games in Nanjing, China on Wednesday.
Vien finished first in the girls' 200m backstroke, while Truc Mai won the girls' long jump event by clearing 5.9 meters.
Vien covered the distance in 2 minutes 12.65 seconds, beating South Korean runner up Im Dasol, who came 2.44 seconds behind her.
The day before, Vien won the silver medal in the girls' 100m backstroke with a time of 1:3:46, losing to Dasol, who finished in 1:3:08.
Vien has been the most successful Vietnamese athlete at the second edition of the Asian Youth Games.
Mai won the girls' long jump of 5.9 meters beat out second-placed host jumper Hong Jun Wen (5.78m). Thai jumper Chuamaroeng (5.61m) took the bronze.
Also on Wednesday, Tran Thi Mai won the silver medal in the girls' 2,000m steeplechase while Truong Thi Kim Tuyen earned the bronze medal in the girls' 43 kg division of the tae kwon do event.
In tennis, 16-year-old Ly Hoang Nam beat Yang Shao-Chi of Taiwan in straight sets in the quarterfinals, earning the right to play Dmitry Popko of Kazakhstan in the semifinals.
It has been predicted that Nam, who is ranked 140th by the International Tennis Federation (ITF), will beat the 259th-ranked Popko, who was lucky to advance to the semis when top seed Zheng Wei Qiang of China, ranked 53rd by the ITF, had to withdraw from the competition in the third set of the quarterfinal play due to an injury.
The Vietnamese sports delegation is now in 10th position at the contest with two gold medals, three silvers and one bronze. China is on top with 34 gold medals, followed by second-placed South Korea with 13 gold medals.