Two-time Olympic champion Viktor Axelsen made a comeback on Wednesday after a seven-month absence from badminton.
However, the Dane never came close to progressing to the second round of the Super 500 tournament Hong Kong Open, where he was the defending champion.
Axelsen lost 15-21, 7-21 to the fifth-seeded Japanese Kodai Naraoka.
Axelsen had won the six previous matches between the two and was also a relatively clear favorite with the bookmakers.
But it soon became clear that the Dane is far from his usual form.
Naraoka took a 7-3 lead straight from the start, and even though Axelsen managed to restore parity at 10-10, Naraoka was by far the superior player.
Five cuccessive Japanese points and a number of Danish mistakes allowed Naraoka to pull ahead and win the first set and after a close beginning to the second set, Axelsen resigned.
6-5 quickly turned into 21-7, and Axelsen seemed to be far from his usual powerful self.
Already before the match, Axelsen indicated that he did not have "sky-high" expectations for himself, even though he has trained well.
"I am far from being 100 % at my usual level. I could have spent a little more time preparing, but it's not that important. The most important thing is that I am in a place where I feel comfortable going onto the court in a tournament", Axelsen told DR Sporten.
He has suffered from a "disc in his lower back which has pushed a nerve and caused constant pain" in his left leg, which is why he had binocular surgery in April.