Philadelphia, Oct 11 (IANS): Malaysia's Nicol David is seeded to become the first player for more than 20 years to successfully defend the Women's Delaware Investments US Open title when the Women's Squash Association (WSA) World Series Platinum event gets underway here Friday at Drexel University.

David, who won the title last year for the first time, is back in top form. After her shock British Open final defeat in May, the world number one from Penang bounced back with successive title triumphs in September's Malaysian Open on home soil and last week's Carol Weymuller Open in New York.

The 30-year-old begins her defence against a qualifier - with her likely second round opponent being France's Camille Serme in a repeat of the Carol Weymuller climax.

David's toughest assignment en-route to the final is likely to be in the semi-finals -- against fourth seed Alison Waters, the world no.4 from England who was runner-up in 2009.

Laura Massaro, 2011 champion, is the event's no.2 seed. The World No.2 from England lost out to Egypt's Raneem El Weleily in last year's semi-finals and is scheduled to meet the World No.3 from Cairo at the same stage next week.

But first, 29-year-old Massaro faces compatriot Victoria Lust in the opening round -- and a predicted clash with England team-mate Jenny Duncalf, the 2009 champion, in the quarter-finals.

Amanda Sobhy leads US interest in the championship. Promoted to 16th seed following the withdrawal of England's injured Sarah-Jane Perry, 20-year-old New Yorker Sobhy has a tough first round opponent in Nicolette Fernandes, the new World No.19 from Guyana.

Qualifying gets underway Friday in Philadelphia, where Sabrina Sobhy will be hoping to join her older sister in the main draw for the first time after taking on Australian Melody Francis.