KARACHI, Sept 5: Carla Khan upset the form book in the quarterfinals of the Women's Sports World Mexican Open squash championship when she triumphed in five games over England's second seed Jenny Duncalf in Mexico City.

According to details made available here on Sunday, England-born Khan fought back from a game down against her higher-ranked opponent to take a 2-1 lead. But Duncalf, the world No12 from Yorkshire who has just been selected to make her England debut in this month's World Team Championships in Amsterdam, reasserted her authority on the match to draw level.

In the closely-contested decider, sixth seed Khan edged ahead to claim her notable 4-9, 9-4, 9-6, 3-9, 9-7 victory and a place in the semifinals against seventh seed Annelize Naude, who also scored an upset over an English player when she beat third-seeded Stephanie Brind 8-10, 9-6, 10-8, 9-7.

The other semifinal will be the encounter predicted by seedings, when top seed Vanessa Atkinson takes on Scotland's fourth seed Pamela Nimmo. Atkinson, the world No 3 from the Netherlands, beat fifth seed Latasha Khan of the USA, 9-6 9-7 9-5, while Nimmo needed four games to overcome Egypt's eighth seed Engy Kheirallah 9-6 9-4 5-9 9-1.

QUARTERFINAL RESULTS: [1] Vanessa Atkinson (Netherlands) bt [5] Latasha Khan (USA) 9-6, 9-7, 9-5; [4] Pamela Nimmo (SCO) bt [8] Engy Kheirallah (EGY) 9-6, 9-4, 5-9, 9-1; [7] Annelize Naude (NED) bt [3] Stephanie Brind (ENG) 8-10, 9-6, 10-8, 9-7; [6] Carla Khan (PAK) bt [2] Jenny Duncalf (ENG) 4-9, 9-4, 9-6, 3-9, 9-7. -PPI