Nehwal struggled from the outset, allowing her unranked opponent to dictate proceedings and Tai duly took advantage, claiming the first game 21-15.

The clear outsider in the contest, the momentum remained with the player from Chinese Taipei and she then managed to wrap up a convincing victory by clinching the second 21-16 to inflict a premature exit on the Indian star.

The day of surprises in the women’s singles draw continued when number three seed Li Xuerui of China, the Olympic champion, was also beaten by compatriot Wang Shixian.

Li, a double World Championships silver medallist, moved to within one game of the semi-finals by taking the first but her team-mate launched a spirited fightback, sealing a marathon 16-21, 21-17, 21-18 triumph in a match that lasted for one hour and 16 minutes.

There were no such worries for women’s top seed Carolina Marin of Spain as the 22-year-old double world champion enjoyed serene progress to the last four with a 21-17, 21-19 success in her clash with Thailand’s Ratchanok Intanon.

The favourites in the men’s singles competition also struggled on a day packed full of shock results as unseeded Chinese player Xue Song knocked out sixth seed Viktor Axelsen of Denmark with a hard-fought 21-19, 23-25, 21-11 win.

Chinese fifth seed and two-time Olympic champion Lin Dan accounted for Denmark’s Jan Ø. Jørgensen, seeded third, as he booked his place in the last four by virtue of being on the right side of a 10-21, 21-9, 21-15 scoreline.

South Korea men’s doubles top seeds Lee Yong-dae and Yoo Yeon-seong are safely through after they overcame English pair Marcus Ellis and Chris Langridge 21-17, 21-11.

There was success for the host counry as the husband and wife team of Chris and Gabby Adcock reached the semi-finals of the mixed doubles competition, proving too strong for Indonesian second seeds Tontowi Ahmad and Lilyana Natsir, claiming a 21-18, 21-6 victory.

The tournament in Birmingham is due to continue tomorrow.