The 21-year-old World Tour Finals winner won the opening event of the World Tour season, the Malaysia Masters, on Sunday (January 12).

But she fell at the first hurdle this time, as Kjærsfeldt won 21-18, 21-14 at Jakarta's Istora Gelora Bung Karno.

"I'm so happy, I played a good match against her last week and she won the tournament, and I also knew maybe she was tired today, so I just had to go in and give all I had, see how it goes, and I won and I'm so happy," the Dane said.

"I had the whole of December training and it was a year with a lot of tournaments, so it was nice to focus on training, and get in better shape and it's paying off now."

Japan's second seed Akane Yamaguchi also suffered a scare as she fell behind to Indonesia's Gregoria Mariska Tunjung, before winning 12-21, 21-15, 24-22.

India's reigning world champion and fifth seed PV Sindhu also had to battle back, defeating Japan's Aya Ohori, 14-21, 21-15, 21-11.

Spanish Olympic champion Carolina Marin beat Thailand's Nitchaon Jindapol 21-13, 21-15.

There was also a shock in the men's draw, with Chinese Taipei's second seed Chou Tien-chen losing 21-12, 21-17 to Hong Kong's Lee Cheuk Yiu.

Denmark's defending champion Anders Antonsen, the fourth seed and World Championship runner-up, saw off South Korea's Son Wan-ho 21-10, 21-18.

Another Dane, fifth seed and 2017 world champion Viktor Axelsen, won 21-12, 21-14 against China's veteran Lin Dan, the Beijing 2008 and London 2012 Olympic champion.

The Super 500 tournament continues tomorrow.

Competition has been overshadowed after Japan's world number one player Kento Momota was involved in a traffic accident after winning the men's event in Malaysia, which killed his driver.

Momota suffered multiple laceration wounds to the face and a fractured nose, but had already withdrawn as the top seed in Indonesia.

He is a big Japanese hope for home gold at the Tokyo 2020 Olympics.