The top seeds were upset in the semi-finals of the women's squash world tour event at Heights Casino in New York on Saturday.

England's world number six Jenny Duncalf pulled off the most impressive win of her career when she beat Malaysia's world number one Nicol David 11-6 11-4 11-3.

Earlier, third seed Alison Waters upset Australia's second seed Rachael Grinham 11-9 11-1 11-2, setting up the first all-English US Open final since 1993.

Not only was the stunning win Duncalf's first over David in 15 Tour meetings since February 2002, but it was also the dominant Malaysian's first straight games defeat since April 2007.

"Im pretty shocked," said the 26-year-old Duncalf.

"One for winning - but certainly for winning 3/0. I felt calm all the way through till the end when I thought 'don't mess this up now!'

"I always enjoy playing this tournament and if I was going to beat Nicol, there was a good chance it would be here."

David, who celebrated her 40th successive month at the top of the world rankings this month, was philosophical about her defeat.

"With all the girls, they are working really hard and going out and giving it everything. She didn't let up an inch and I just had to try and do something and she just kept on going and went right through."

Rachael Grinham, the world No.4 and four-time British Open champion, was 6-4 up on Alison Waters before their clash - but the world No.5 from London had been successful in their most recent meeting, in August's Malaysian Open.

The higher-ranked Australian built up an early lead, but once Waters found her rhythm there was no turning back.

"I was really pleased to win 3/0 as Rachael is a great player," said Waters.

"We've had really close matches in the past so I knew that it could be very tough."

Grinham added: "I started off OK and then Ali settled into it. I wasn't covering the court the way I needed to. She played really well and is improving all the time."

The final will mark the English pair's third meeting this year - the first going to Duncalf in February's British National Championship final, and the second to Waters in the Singapore Masters in September.