It came with second seed Kento Momota, Japan's Asian and world champion, unable to contest his quarter-final because of injury at Seoul's SK Handball Stadium.

Ginting, whose season hit the heights last week as he beat the all-conquering Momota in the China Open final, was beaten in just 39 minutes by Chou, who earned a 21-13, 21-11 scoreline.

Chou's semi-final opponent will be Japan's Kenta Nishimoto, who received a walkover from his injured compatriot Momota.

Meanwhile, the player Ginting beat in last year's final, his Indonesian compatriot Jonatan Christie, progressed.

The Asian Games champion beat China's Zhao Junpeng 21-17, 21-16.

"This is the first semi-final for me in 2018, so I'm very very happy," the Indonesian said.

"After the Asian Games, I was a bit tired, and there was no time to prepare for the next three tournaments.

"In Japan and in China I lost early.

"So today I'm happy that in the last tournament of the Asian leg I reached the semi-finals."

Christie now faces senior compatriot Tommy Sugiarto, who outplayed Korean qualifier Heo Kwang Hee in three games, winning 15-21, 21-19, 21-9.

Nozomi Okuhara reached her third consecutive World Tour semi-final in the women's event after surviving four match points.

Japan's 2017 world champion eventually defeated an exhausted Saina Nehwal of India 15-21, 21-15, 22-20.

Okuhara takes on compatriot Akane Yamaguchi, while in the other semi-final, home hope Sung Ji Hyun faces Beiwen Zhang of the United States, who beat Scotland's unseeded Kirsty Gilmour 21-15, 21-19.