BIRMINGHAM - Malaysia’s Lee Zii Jia may believe he is still struggling for form but the world No. 4 is the highest ranked men’s player still alive at the semi-final stage of the All England Open.

He claimed a deciding game against Japan’s Kodai Naraoka on Friday to progress to the last four in Birmingham 21-9, 10-21, 21-13.

“I’m maybe at 70 per cent of my best at the moment. I’m still trying to find the best version of me,” he said.

He next faces China’s Shi Yuqi after the 2018 All England winner comfortably saw off compatriot Weng Hong Yang 21-9, 21-16.

Anders Antonsen shocked world No. 3 Anthony Ginting 21-14, 9-21, 21-17.

The Dane will face Li Shi Feng, who saw off world No. 1 Viktor Axelsen’s conqueror Ng Tze Yong 21-11, 21-11.

The top seeds have found it much smoother in the women’s tournament with the semi-finals set to be contested by the top four players in the world.

Defending champion Akane Yamaguchi beat China’s Wang Zhiyi 21-19, 21-12 to reach the last four.

Chen Yufei awaits Yamaguchi in Saturday’s semi-finals after the Olympic champion also needed just two games to see off Gregoria Mariska 24-22, 23-21.

South Korean An Se-young enjoyed a walkover into the last four after illness forced Spain’s Carolina Marin to withdraw.

Tai Tzu-ying completes the semi-final line-up after she saw off He Bingjiao 21-12, 21-11. AFP