A pair of Pakistanis led a remarkable day of upsets in the opening round of the EBS Dayton Open when qualifiers Danish Atlas Khan and Yasir Butt overpowered higher-ranked opponents to reach the quarter-finals of the PSA World Tour International 25 squash event in its eighth year at the Dayton Squash Center in Dayton in the US state of Ohio.

Kahn, a 17-year-old from Peshawar, came back from a game down to beat Egypt's former world junior champion Amr Khaled Khalifa 10-12, 11-5, 11-9, 11-7 in 58 minutes - while Butt, 23, from Lahore, battled for 85 minutes to tame England's Robbie Temple 15-13, 7-11, 11-7, 8-11, 11-9.

And a third qualifier made it through to the last eight when England's Olivier Pett ousted Canadian Shawn Delierre 12-10, 12-14, 12-10, 11-7.

"Our Pakistani members cheered Khan & Butt on to victory - but stayed to help push qualifier Pett past Delierre of Canada," said tournament organiser Charlie Johnson.

But the upsets continued: New Zealand's unseeded Campbell Grayson got the better of in-form Mexican Arturo Salazar, beating the third seed 11-8, 11-3, 11-5.

England's fourth seed Chris Simpson played one of the best matches in recent times to overcome Egypt's reigning world junior champion Marwan El Shorbagy 11-7, 11-8, 11-9 in just 35 minutes.

"Won my match against world junior champion Marwan el Shorbagy 3/0, really happy with my performance, nice to get a good win in!" tweeted the delighted Guernsey-born 24-year-old later.

But the top two seeds restored some order to the well-established Tour event: English favourite Adrian Grant, the world No17 from London, defeated rising Australian star Zac Alexander 11-9, 11-9, 11-5, while Alister Walker, the No2 seed from Botswana, held off the challenge of Henrik Mustonen, beating the promising Finn 11-8, 11-8, 11-5.

RESULTS: PSA International 25 EBS Dayton Open, Dayton, Ohio, USA

1st round:
[1] Adrian Grant (ENG) bt Zac Alexander (AUS) 11-9, 11-9, 11-5 (60m)
[Q] Danish Atlas Khan (PAK) bt Amr Khaled Khalifa (EGY) 10-12, 11-5, 11-9, 11-7 (58m)
[Q] Yasir Butt (PAK) bt Robbie Temple (ENG) 15-13, 7-11, 11-7, 8-11, 11-9 (85m)
Campbell Grayson (NZL) bt [3] Arturo Salazar (MEX) 11-8, 11-3, 11-5 (38m)
[4] Chris Simpson (ENG) bt Marwan El Shorbagy (EGY) 11-7, 11-8, 11-9 (35m)
Adrian Waller (ENG) bt [Q] Scott Arnold (AUS) 11-7, 11-8, 11-8 (42m)
[Q] Olivier Pett (ENG) bt Shawn Delierre (CAN) 12-10, 12-14, 12-10, 11-7 (68m)
[2] Alister Walker (BOT) bt Henrik Mustonen (FIN) 11-8, 11-8, 11-5 (38m)

Quarter-final line-up:
[1] Adrian Grant (ENG) v [Q] Danish Atlas Khan (PAK)
Campbell Grayson (NZL) v [Q] Yasir Butt (PAK)
[4] Chris Simpson (ENG) v Adrian Waller (ENG)
[2] Alister Walker (BOT) v [Q] Olivier Pett (ENG)

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