Jang Ji-Won won South Korea's first taekwondo gold medal at the Olympics by beating American Nia Abdallah 2-1 in the women's featherweight final.
Jang scored a one-point kick in the first round before she widened the lead to 4-1 after three - two points were deducted for penalties.
Mexican Iridia Salazar beat Sonia Reyes of Spain 3-2 to win bronze.
Meanwhile, Iran's Hadi Saei Bonehkohal beat Taiwan's Huang Chih Hsiung 4-3 to win the men's featherweight title.
South Korea's Song Myeong-Seob grabbed the bronze with a 12-7 victory over Diogo Silva of Brazil.