Zulfadli Zulkiffli booked his place in the second round of the World Championships in Jakarta on Monday after recording a shock defeat over sixth seed Chou Tien Chen.
The Malaysian number two, who was told prior to the event by Badminton Association of Malaysia (BAM) technical director Morten Frost Hansen that he wasn't good enough to win the tournament, made a cracking start against the sixth seed from Chinese Taipei, winning the first game 21-15.
The second game was a much closer affair but the 22-year-old former world junior champion kept his wits about him to win the second game 22-20 in a match that lasted 38 minutes.
He will take on Ireland's Scott Evans for a place in the last 16.
Zulfadli will be joined in the second round by Tee Jing Yi, who won a one-sided match against Italy's Jeanine Cicognini.
Tee dominated the 26-minute match from start to finish to post a 21-13, 21-8 victory.
Their Malaysian compatriat Lyddia Yi Yu Cheah was knocked out at the first stage, though, losing 25-23 21-13 to Turkey's Ozge Bayrak.
Former world number one Lee Chong Wei starts his campaign in the Indonesian capital on Tuesday against Turkey's Kestutis Navickas.
Tee Jing Yi will face a tough task if she is to advance to the second round, since she faces defending champion and world number one Carolina in her opener.