BANGKOK, Dec 8 ― Top-ranked women's singles star Akane Yamaguchi suffered a shock defeat at the season-ending Badminton World Tour Finals in Bangkok on Thursday at the hands of Olympic champion Chen Yufei.

The Badminton World Federation shifted the US$1.5 million (RM6.6 million) flagship event to Bangkok's Nimibutr Arena because tough pandemic restrictions forced the tournament out of Guangzhou in China.

It was a vital win for fourth-ranked Chen ― who had a disappointing opening round, losing to Indonesian rising star Gregoria Mariska Tunjung on Wednesday.

Chen claimed the first game 21-19 but only after Yamaguchi ― who retained her world title in August ― saved three game points.

Yamaguchi showed some flashes of brilliance in the second and looked like she was on the verge of securing a tie breaker, but squandered a four-point advantage at the interval.

Chen fought back to even the scores and ultimately claim the second game 21-18 and victory in 49 minutes.

Meanwhile, South Korean young gun An Se Young, 20, kept her hopes alive, beating Tunjung ― also a crucial win after a loss a day earlier to Yamaguchi.

She made quick work of Tunjung, powering home in the first game 21-9.

But the Indonesian dug deep and found momentum in the second to level 21-11, before the defending champion held her nerve to claim the final game 21-10.

In the men's draw, seventh-ranked Indonesian Anthony Ginting bolstered his chances of a semi-final berth, beating Taiwan's Chou Tien Chen 21-14, 12-21, 21-19. ― AFP