India’s Lakshya Sen is guaranteed to win his first badminton world junior championship medal after reaching the semi-finals on Friday.

Sen, the fourth seed, beat the unseeded Aidil Sholeh Ali Sadikin of Malaysia in straight games 21-8, 21-18 to book a spot in the last four.

The 17-year-old Indian has largely been untroubled in the tournament so far. The only game he lost in the four matches he has played so far was against ninth seed Chen Shiau Cheng in the fourth round.

Sen will be up against top seed and defending champion Kunlavut Vitidsarn in the semi-finals but he should take confidence from the fact that he beat the Thai in the final of the Asian Junior Championships earlier this year. The two shuttlers have played each other only once.

The second men’s singles semi-final will be between third seed Li Shifeng of China and Japan’s Kodai Naraoka.

Sen will be the only Indian in the semi-finals, after men’s doubles pair Vishnu Vardhan Goud and Srikrishna Sai Kumar Podile lost to 10th seeds Tae Yang Shin and Chan Wang of Korea 11-21, 8-21.