Australia's Donna Urquhart recorded her first career win over compatriot Rachael Grinham to advance to the quarter-finals of the Australian Open squash tournament in Canberra on Thursday as four of the top eight women's seeds bowed out.
The 25-year-old came out firing against seventh seed Grinham then overcame a third-game stumble to triumph 11-5 11-7 6-11 11-4.
Urquhart played brilliantly against former world No.1 Grinham, using her reach and height effectively as she dominated her smaller opponent at the front of the court.
Englishwoman Jenny Duncalf (second seed), Hong Kong's Annie Au (fifth seed) and Frenchwoman Camille Serme (sixth seed) all lost their second-round matches on a day of upsets.
Australia's eighth seed Kasey Brown regrouped after losing the first game to notch a 7-11 11-4 11-6 11-9 win over New Zealand's Joelle King.
Urquhart will face Englishwoman Laura Massaro after the third seed recorded a hard-fought 14-12 11-8 11-9 victory over fellow countrywoman Emily Whitlock.
"It was a little bit quick. I couldn't believe it was happening like that," Urquhart said of the first two games.
"I felt in control and I was in front just by volleying and getting up high on the T.
"She made a few errors as well, but I think I was making it hard for her because I was in front on the court. But I was surprised to find myself two-love up - I've never even got more than one game off her in a tournament match."
Earlier, former world junior champion Amanda Sobhy of the US produced some stunning squash to send Duncalf packing.
Duncalf, who lost last year's Australian Open final to Malaysia's Nicol David, had no answer against Sobhy, who combines her squash career with fulltime study at Harvard University.
Sobhy took early control of the match and, although Duncalf fought her way back into the clash, the American finished strongly for a 11-7 10-12 11-7 11-6 win.
Au, who won the Australian Open in 2008, went down to 2010 runner-up Alison Waters of England 11-7 11-6 11-8, while Indian glamour girl Dipika Pallikal started sluggishly but bounced back to defeat Serme 3-11 11-9 11-9 11-6.
There were no such problems for top seed David, who easily accounted for fellow Malaysian Low Wee Wern 11-4 11-1 11-6.
Ireland's Madeline Perry, the 2010 champion, also progressed with a 11-8 13-11 11-2 victory over England's Emma Beddoes.