Olympic champion Carolina Marin withdrew through illness ©Getty Images

The reigning Olympic and world champions both exited the women's draw in the first round, as the Badminton World Federation Fuzhou China Open began today.

Rio 2016 gold medallist Carolina Marin retired while trailing Chinese Taipei's top seed Tai Tzu-ying 21-16, 13-1.

Marin, a three-time world champion, beat Tai in the final of the China Open in September in only her second tournament back after eight months out following ACL reconstruction surgery.

The Spaniard has still not worked her way back into the seeded positions and withdrew today due to fever and a throat infection. 

She was joined in exiting the World Tour Super 750 event at Haixia Olympic Sports Center by this year's world champion PV Sindhu, as the Indian sixth seed was shocked by Chinese Taipei qualifer Pai Yu-po, 21-13, 18-21, 21-19.

Sindhu was 11-3 down in the decider before recovering to lead 18-15, but Pai turned things around to claim one of the biggest wins of her career.

Chinese Taipei qualifer Pai Yu-po claimed one of the biggest wins of her career ©Getty Images
Chinese Taipei qualifer Pai Yu-po claimed one of the biggest wins of her career ©Getty Images

There was a straightforward passage for Japan's 2017 world champion Nozomi Okuhara, the fourth seed who beat China's Chen Xiaoxin 21-16, 21-6.

In the men's draw, top seed and back-to-back world champion Kento Momota of Japan also saw his opponent withdraw.

He won the first game 21-17 against Liew Daren before the Malaysian pulled out.

Denmark's seventh seed and 2017 world champion Viktor Axelsen made it through with a 21-15, 21-19 win over Japan's Kanta Tsuneyama.

Indonesian eighth seed Anthony Sinisuka Ginting was knocked out, however, losing 21-18, 21-9 to Ng Ka Long of Hong Kong.

The tournament continues tomorrow with the remainder of the first-round clashes.