Paris Olympics gold medallist An Se-young beat Japan's Akane Yamaguchi 21-15 21-12 in the last four of badminton's World Tour Final in Hangzhou on Saturday to set up a title clash with defending champion Wang Zhiyi.

Bidding for a second title at the season-ending championships, South Korea's An came at the world champion with power and pace but Yamaguchi repelled the attacks with pinpoint accuracy from the front court.

An's pressure eventually told, however, and she kept Yamaguchi off balance to take the match with quick rallies.

In the second women's semi-final, Wang, 25, dropped the first game to Ratchanok Intanon, who caused the Chinese player all sorts of problems with the variety of her shots.

The Thai defended well on the back court but Wang ticked up the aggression to take the second game.

Wang's superior fitness began to tell in the third as the 30-year-old Ratchanok tired and the Chinese player emerged with a 15-21 21-17 21-11 win to reach the final.

On the men's side, Christo Popov defeated Japan's Kodai Naraoka's 21-19 21-8 to reach the final in his tournament debut as a singles' player.

He will face the winner of the second semi between Paris Olympics silver medallist Kunlavut Vitidsarn and China's world champion Shi Yuqi, scheduled to take place later in the day.

Naraoka displayed patience early on to slow Popov, but the Frenchman found success targeting his opponent's backhand before an unforced error from the Japanese player allowed Popov to take the lead.

Gaining confidence, Popov up the pace of his attacks with faster serves in the second game and picked up what was a comfortable win in the end.

-Karan Prashant Saxena/Reuters