Alison Waters stunned onlookers at Casino Heights in New York as she dismissed world No.1 Nicol David in the quarter-finals of theWSA Gold Series Carol Weymuller Open.

The English qualifier took four games to subdue the reigning World Champion, who lost out to Raneem El Weleily in last week’s CIMB Malaysian Open, making it David’s first consecutive tournament losses since 2009. Waters will now face compatriot Laura Massaro in the semi-final. The world No.3 beat Hong Kong international Annie Au after coming from behind in a similar pattern to her first round clash.

Teenager Nour El Sherbini beat higher seed Jenny Duncalf in straight games to prolong the Egyptian’s maiden Carol Weymuller campaign and continue Duncalf’s wait for a semi-final appearance stretching back to January.

Sherbini will face Raneem El Weleily in the second semi-final of the event, as the world No.2 fought back from two games down to defeat unseeded Joelle King of New Zealand in five games. The final result could have gone either way as little separated the pair in the fifth game, and a tiebreak was forced before the Egyptian was able to finish off the tie.

WSA $50k Carol Weymuller Open, New York, USA:

Quarter-finals:
[Q] Alison Waters (ENG) bt [1] Nicol David (MAS) 11-9, 5-11, 11-3, 11-7
[4] Laura Massaro (ENG) bt [6] Annie Au (HKG) 9-11, 11-4, 11-3, 11-6
[7] Nour El Sherbini (EGY) bt [3] Jenny Duncalf (ENG) 11-6, 11-9, 11-6
[2] Raneem El Weleily (EGY) bt Joelle King (NZL) 3-11, 10-12, 11-3, 11-9, 13-11