Unified pair Jang Woojin, of South Korea, and Cha Hyo Sim, from North Korea, energised the opening day of the International Table Tennis Federation's World Tour Grand Finals in Incheon by beating the world champions to reach the last four of the mixed doubles.
The pairing, seeded second, received huge support in the South Korean city as they beat Japan's Maharu Yoshimura and Kasumi Ishikawa 12-10, 8-11, 11-5, 9-11, 11-5 at Incheong's Namdong Gymnasium.
It means they have earned a semi-final against home pair Lim Jonghoon and Yang Haeu tomorrow.
"It was an honour just to play the match in our country and by winning the match, I was glad to return the fans' cheering and support," said Jang.
"We shall try harder and train more now to win the next game.
"I felt the same support when we played together in Daejeon earlier this year - I realised how the fans can really give me greater strength.
"I believe that the fans cheering me can actually turn into additional points in the game, enabling us to win."
China's defending women's singles champion Chen Meng was made to battle all the way by compatriot Chen Xingtong before winning 11-7, 9-11, 11-7, 11-6, 8-11, 9-11, 11-5.
Chinese top seed Wang Manyu had an easier passage as she defeated Singapore's Tianwei Feng 11-3, 10-12, 11-6, 11-6, 11-5.
Ishikawa, having been beaten by the Unified Korea pairing in her earlier match, recovered to win her opening singles match against compatriot Miu Hirano 11-6, 11-3, 9-11, 11-8, 11-7.
But for Japan's 18-year-old rising star Mima Ito the opening match against Chinese Taipei's Cheng I-Cheng proved to be a gruelling defeat as she went down 9-11, 11-3, 7-11, 11-6, 11-8, 8-11, 7-11.
Last year's men's singles champion Fan Zhendong of China starts his title defence tomorrow against Japan's Koki Niwa.
In other men's singles matches today, Fan's compatriot Xu Xin earned an 11-6, 9-11, 11-3, 11-8, 11-7 win over Hong Kong's Wong Chun Ting.
Japan's Masataka Morizono and Yuya Oshima, who took the men's doubles title in the Kazhak city of Astana last year, were seeded second in Incheon and lived up to their billing with an 11-5, 11-8, 11-3 win over eighth seeds Nandor Ecseki and Adam Szudi of Hungary.
They will next meet Hong Kong's number three seeds Ho Kwan Kit and Wong Chun Ting in the semi-finals.
The Hong Kong pairing earned an 11-2, 11-2, 8-11, 11-9 win over Chen Chien-An and Chuang Chih-Yun of Chinese Taipei.
The host nation's top seeds Jeoung Youngsik and Lee Sangsu crushed Hong Kong's Lam Siu Hang and Ng Pak Nam 11-7, 11-7, 11-3.