JAKARTA (AFP) - Badminton world No. 1 Lee Chong Wei was on course for his fifth Indonesia Open Super Series title, after defeating Dionysius Hayom Rumbaka in the semi-finals on Saturday.

The Malaysian will face Marc Zwiebler in the men's singles final in Jakarta on Sunday, after the German beat Indonesian Tommy Sugiarto in his semi-final.

Lee played a series of powerful smashes and smooth drop shots to convincingly defeat the 24th-ranked Rumbaka of Indonesia 21-17, 21-14 in 39 minutes.

Rumbaka, who stunned world No. 3 Du Pengyu of China in Friday's quarter-final, proved no match for Lee's superior technical skills and experience.

"Hayom (Rumbaka) has improved a lot. He played much better than before," Lee said of his opponent.

Zwiebler beat Sugiarto 21-17, 21-10 in 37 minutes.

The German said he was "not expecting to win" against Lee.

"I have no pressure. I just want to give everything I have to put on a good show, to put on a good fight and to annoy him as much as I can," he said.

In the women's singles, defending champion Saina Nehwal of India went out after losing to Germany's Juliane Schenk in a gruelling three-set match that ended 12-21, 21-13, 21-14 and lasted 52 minutes.

Schenk will take on world No. 1 Li Xuerui of China in the final.

Li advanced to the last round after beating Hong Kong's Yip Pui Yin 17-21, 21-11, 21-11.