China won four of the eight gold medals on offer at the World Taekwondo Grand Prix, which ended in Sofia on Sunday.
Rio Olympic champion Zhao Shuai and Zhou Lijun won the first two titles for China on Friday. Zhao smashed South Korea's Lee Dae-hoon 17-7 in the men's -68kg category, and Zhou defeated another South Korean, Lee Ah-reum, 15-12 in the women's -57kg category.
Zheng Shuyin, also Rio Olympic champion, snatched the third gold medal for China after beating Bianca Walkden of Britain 3-2 in the women's 67kg category on Saturday.
On Sunday, Beijing 2008 and London 2012 champion Wu Jingyu won the last title for China in Sofia. In the women's -49kg category, Wu totally outplayed 2016 Rio gold medalist Kim So-hui of South Korea 24-8.
The other four gold medals went to South Korea, Brazil, Cote d'Ivoire and Jordan.
The three-day competition took place at the Exhibition Forum Event Center in Sofia's Hotel Marinela, bringing together the world top 32 athletes.
It was the first time the elite Grand Prix series had come to Bulgaria, which will next year host the World Taekwondo Junior Championships.