DAEJEON, South Korea, July 19 (Xinhua) -- A mixed doubles pair from the Democratic People's Republic of Korea (DPRK) defeated the reigning champions here on Thursday at the Seamaster 2018 International Table Tennis Federation (ITTF) World Tour Platinum Korea Open.

The DPRK duo of Pak Sin Hyok and Kim Nam Hae beat Japan's Masataka Morizono and Mima Ito, the top seeds and reining champions, 5-3 (11-5, 8-11, 11-5, 7-11, 14-12) in the opening round of the mixed doubles event.

It was an agonizing match for the Pak and Kim as they faced deuce in the fifth game, but it ended up in a dramatic victory for the DPRK, which is competing in the South Korea-hosted event for the first time.

Meanwhile, a unified Korean team of South Korea's Jang Woo-jin and the DPRK's Cho Hyo Sim also took a surprising victory, beating No.2 seeds Wong Chun Ting and Doo Hoi Kem of Hong Kong, China, in the qualification round.

"At first I was quite nervous and did not do as well as I hoped, but Hyo Sim encouraged me. She helped by taking the lead. It helped me relax and I managed to play better after that," said Jang.

Elsewhere, China's Wang Chuqin and Sun Yingsha won by a walkover in the opening round, as Japan's Tomokazu Harimoto and Hina Hayata were forced to withdraw amid an injury to the latter. The Chinese pair will take on the DPRK's Pak and Kim in the quarterfinals.

The Korea Open kicked off on Tuesday in Daejeon, some 160 km south of the capital Seoul, and lasts until Sunday, with around 230 players from 27 countries and regions participating.