The eighth seed, a two-time world medallist and last year's runner-up in the women's singles event, fell to a 15-21, 21-23 defeat at Odense Sports Park in this BWF Super 750 tournament.

Takahashi now faces a second-round meeting with South Korea's Kim Ga Eun, a 22-20, 21-16 victor over Malaysia's Soniia Cheah.

The player who beat Nehwal in the 2018 final, fourth-seeded Taiwanese Tai Tzu Ying, overcame Thailand's Nitchaon Jindapol 21-15, 21-9 in the first round.

Sixth-seeded Thai Ratchanok Intanon had a walkover win against Denmark's Mia Blichfeldt, who was forced to withdraw from the event due to an injury she picked up in training.

In the men's singles event, all four seeded players in action today progressed through to round two.

Second-seeded Taiwanese Chou Tien Chen beat China's Lu Guang Zu 21-13, 17-21, 21-17, while fourth-seeded home favourite Anders Antonsen, the 2019 world silver medallist, defeated India's Srikanth Kidambi 21-14, 21-18.

Antonsen's compatriot Viktor Axelsen, the seventh seed and 2017 world champion, overcame Japan's Kenta Nishimoto 21-19, 21-19.

There was also a win for fifth-seeded Chinese Chen Long over Malaysia's Lee Zii Jia, with the reigning Olympic champion triumphing 21-18, 15-21, 21-16.

Competition is due to continue until Sunday (October 20).