Sim Jae-young won a second successive women's under-46kg world title as South Korean athletes claimed all three gold medals on offer on the opening day of finals at the World Taekwondo Championships here.
The South Korean star defeated Iran's Mahla Momenzadeh 11-6 to add to her 2017 victory.
It was the start of a string of golds for her country as compatriot Jang Jun reigned supreme in men's under-58kg final.
The Asian Games champion defeated Mexico's Brandon Plaza Hernandez 25-9 to to seal his first world title.
Lee Da-bin, a two-time Asian Games champion, then secured gold at her debut tournament.
The 22-year-old thrashed Mexico's Maria Espinoza 22-2 in the women's under-73kg final.
The gold-medal bouts may have been all about South Korea but the evening's semi-finals were dominated by the host nation.
Britain's Bianca Walkden, seeking her third consecutive world title, started the proceedings with a straightforward 19-9 victory over Mexico's Briseida Acosta in the over-73kg division.
Walkden will now face Olympic champion Zheng Shuyin in the final, which will take place tomorrow.
The Chinese athlete had beaten Croatia's Doris Pole 9-2.
Walken's compatriot Bradly Sinden then caused the upset of the tournament so far against three-time world champion Lee Dae-hoon.
In what was an extremely tight contest, Sinden landed a last-second shot to win 24-23 against the South Korea in their men's under-68kg clash.
He will now face Spain's Javier Perez Polo in the final, who eased past Russia's Alexey Denisenko 12-6.
South Korea will have the chance to claim another gold medalin the men's under-54kg final after Bae Jun-seo defeated Brazil's Paulo Melo 24-16.
Standing in his way will be Russia's Georgy Popov, who secured a 20-14 victory over Iran's Armin Hadipour Seighalani.
The action continues tomorrow.