An Se-young played the game of her life in the semi-finals ©BWF

Number one seed Akane Yamaguchi has been dumped out of the women's Badminton World Federation (BWF) Korea Masters in the semi-finals.

The Japanese star cruised through her quarter-final against Lee Se Yeon of South Korea, 21-9, 21-15, but number seven seed An Se-young of South Korea proved a far more obdurate opponent in the last four. 

An was in control for much of the encounter at Gwangju Women's University Stadium, coming through without dropping a game, 21-16, 21-16.

The second semi-final did go to script, however, with fifth seed Sung Ji-hyun of South Korea up against unseeded Saena Kawakami of Japan. 

Sung was untroubled, winning 21-12, 21-10. 

In the men's draw a surprise victor is guaranteed, with no seeds left in the competition. 

Japan's Kanta Tsuneyama continued his dream run, in an epic three-game encounter with China's Lu Guangzu. 

Tsuneyama took the first game 21-14, but Lu hit back with a 21-18 victory in the second. 

However, Tsuneyama held his nerve and ran out a 21-17 winner in the third. 

But he will be up against it in the final, with China's Lin Dan in imperious form. 

He disposed of Zhao Junpeng easily in his semi-final, 21-12, 21-11. 

Both finals round off the competition tomorrow.