Varma, ranked 57 in the world, plunged the Saarlandhalle into silence as he ousted the number three seed.

The 23-year-old started well and took the first game 21-15.

Roared on by the German crowd, Zwiebler restored parity in the second game, winning it 21-16 to level the contest.

Unfazed by the hostile atmosphere, Varma managed to once again claim the upper hand and went on to win the decisive third game 21-15 to secure his place in tomorrow's semi-finals.

Varma will now take on Denmark's Anders Antonsen for a place in the final after he overcame Germany's Fabian Roth this evening.

Antonsen, seeded 15th, took the first game 21-12 before Roth pinned the Dane back with the help of the home crowd, winning the second game 21-19.

Not effected by the swing in momentum, Antonsen secured his semi-final berth as he claimed the third game 21-14.

The other men's singles semi-final will be contested by another Indian player in Sameer Verma after he coasted past Ukraine's Artem Pochtarov 21-14, 21-16.

He will play the tournament's fourth seed Shi Yuqi of China, who overcame Indonesia's Jonatan Christie 21-17, 8-21, 21-18.

There was another dominant day for Thailand in the women's singles as three of their players advanced to the last four.

Porntip Buranapras had the toughest quarter-final match of all three as she dispatched Spain's sixth seed Beatriz Corrales in straight games, 21-12, 21-7.

Buranapras will now face compatriot Nitchaon Jindapol after she was forced to come back from a game down to beat Chia Hsin Lee of Chinese Taipei.

Lee took the opening game 21-10 before Jindapol, seeded fourth, showed her superiority to overturn the deficit and win the second and third games 21-14, 21-9.

The third Thai player to make it through was 20 year-old Busanan Ongbamrung.

Seeded third in the competition, Ongbamrung thrashed Switzerland's Sabrina Jaquet 21-9, 21-11 inside 27 minutes.

The top seeds in the women's doubles event secured their passage into the semi-finals with a comfortable win.

Chinese duo Chen Qingchen and Jia Yifan defeated Russia's Anastasia Chervyakov and her partner Olga Morozova 21-16, 21-12.

There was an all Danish affair in the the men's doubles quarter-finals today with Kim Astrup and Anders Ska Rasmussen progressing.

Three games were needed to separate the compatriots with unseeded duo Mathias Christians and David Daugaard providing tough resistance.

Astrup and Ska Rasmussen took the opening game 21-18 before their opponents levelled it up by winning the second 21-16.

The sixth seeds, however, rallied to take the third and pivotal game 21-19 in nervy circumstances.

Husband and wife duo, Chris and Gabby Adcock of England, were comfortable winners in the quarter-finals of the mixed doubles competition.

The top seeds won the first game 21-16 before being pegged back by China's Wang Yilyu and Huang Dongping, 21-19 in the second.

The English pair proved too strong however and went on to win in three games, taking the decisive third 23-21.