Tokyo, Jul 28 (IANS): World No.1 shuttler Kento Momota was on Wednesday unexpectedly knocked out of men's singles competition after losing to South Korea's world No.38 Heo Kwang-hee 2-0 in a group stage tie of the Olympic Games here.

Though the Japanese star and top seed had beaten Timothy Lam of the USA in straight games in the first match, Wednesday's 15-21, 19-21 loss to 26-year-old Olympic debutant Heo puts him out of competition.

Momota had to leave the Olympic arena before reaching the last 16.

Before his first-ever journey to Tokyo Olympics, Momota suffered several setbacks. He missed the 2016 Rio Games after receiving a one-year ban from Nippon Badminton Association for gambling at an illegal casino in Tokyo.

In another misfortune, he suffered facial injuries in a car crash in early 2020. He underwent surgery for an eye socket fracture and gradually recovered.

"I had so much support from everyone and a lot of people expected me to win, but I didn't make it tonight. I am very sorry for them," Momota said after Wednesday's loss.

"In the first game, I felt okay. But after the opponent reached 11, I couldn't recover and couldn't motivate myself after that," he said. "I felt that I was really weak tonight."

Heo said he felt less pressure as a lower ranked player he had nothing to lose.

"So I felt less nervous and the result turned out to be good," said Heo. "I am an aggressive player, so I did a lot of training aimed at opponents trying to contain my style of play. This sort of training helps me make fewer mistakes on the court."

Heo, sitting in first place in Group A, will advance directly to the quarter-finals.