Kim So-hui won South Korea's first taekwondo gold medal at the Rio de Janeiro Olympics on Wednesday.

Kim defeated Tijana Bogdanovic of Serbia 7-6 for the women's -49kg title at Carioca Arena 3.

This was the first day of taekwondo competition in Rio, and South Korea has already matched its gold medal total from the 2012 London Olympics. Eight countries split eight gold medals four years ago.

Kim is a two-time world champion making her Olympic debut in Rio.

Kim is 10th on the World Taekwondo Federation's Olympic rankings, three spots above Bogdanovic.

"This was such an incredible victory," Kim said. "I've had to go through a lot just to qualify for the Olympics. I promised my parents I'd bring home a gold medal and I am happy that I kept the promise."

Kim cruised past Julissa Diez Canseco in the round of 16 by 10-2. Then in the quarters, she was trailing Panipak Wongpattanakit of Thailand 4-2 with four seconds remaining, and landed a kick to the opponent's head for the decisive three points.

In the semifinals, Kim and Yasmina Aziez of France were scoreless through three rounds, before Kim scored the clinching point with 36 seconds left in the extra period.

Facing Bogdanovic, the 2015 world bronze medalist, Kim took a

2-1 lead after the first round. Kim kept scoring points but also piling up "kyong-go" (warning) for passive play, gift-wrapping three points for the Serbian.

With Kim nursing a 7-6 lead, Bogdanovic landed what she believed was a valid kick to the trunk at the buzzer. Her coaches requested a video review, conducted with the crowd hushed in anticipation. When the referee signaled the attack was no good, the crowd erupted with a mix of cheers and boos.