There was a big surprise in the Badminton World Championships in Huelva, southern Spain on Monday, when world No. 1 Viktor Axelsen was knocked out of the competition by Singapore's Loh Kean Yew.

Tokyo 2020 Olympic champion Axelsen took the first set 21-14, but the Danish player struggled to find his game in the second set which Loh claimed 21-9 and things got even worse as the favorite took only six points in the decisive set.

"I think he played like a winner today. He definitely deserved the victory, so I wish him all the best for the rest of the tournament," said Axelsen, who admitted that his "first game was OK, but then it was something I'd rather forget."

"Pretty much everything fell apart in the second and third sets. Loh stepped up and I stepped down," he added.

Loh said he was delighted with his surprise win, but confessed he had been worried that Axelsen would "get his confidence back."

"I felt he was under a lot of pressure and he wanted this very much. I'm sure he will come back stronger. I still have a long way to go, I need to be focused for my next match," Loh said.

Axelsen's fellow countryman Anders Antonsen, the No. 3 seed, had a much better day, beating Vladimir Malkov from the Russian Badminton Federation 21-16, 21-13.

Lee Cheuk Yiu of China's Hong Kong Special Administrative Region (SAR) breezed past Howard Shu of the U.S. 21-8, 21-14 in a match that lasted just 28 minutes, while another representative of China's Hong Kong SAR Yip Pui Yin defeated Kristian Kuuba from Estonia 21-11, 21-14.

In the women's singles, Chinese shuttler Zhang Yiman, ranked 46th in the world, upset Hong Kong SAR's Cheung Ngan Yi 21-10, 21-13.

There were mixed fortunes of Chinese players in the men's doubles, where Ou Xuanyi and Zhang Nan disposed of the Indian pair Arun George and Sanyam Shukla 21-15, 21-14.

Another Chinese pair Di Zijian and Wang Chang lost to the Japanese duo Akira Koga and Taichi Saito 21-9, 21-13 as an improvement in the second set was not enough after struggling in the first.