The world's leading players from more than 30 countries have been competing in the Hi-Tec World Squash Championships – Manchester 2008, the first ever joint staging of the Men's World Open and Women's World Open in the UK.
Domestic interest in the men's event expired when the English trio of Nick Matthew, James Willstrop and Adrian Grant all fell at the quarter-final hurdle - leaving Australian David Palmer and three Egyptians Amr Shabana, Ramy Ashour and Karim Darwish to contest the semi-finals.
With 12 successive wins over Duncalf over the past four years, world number two Natalie Grinham was favourite to win their match en-route to her third successive appearance in the women's final.
But a resolute Duncalf, 25, from Harrogate, fought back from two games to one down to beat her Australian-born opponent 11-8 10-12 5-11 11-6 11-7 in 65 minutes to reach her first world semi.
"I played my best ever squash in the fifth game to get to 7-1, then got the tingles when she fought back to win the next four points. A certain English finalist? That's brilliant for English squash," said the former British National Champion.
"I'm really happy to have finally beaten Natalie!"
Duncalf now meets England team-mate and local star Vicky Botwright, the 31-year-old former England No.1 from Manchester who announced her retirement on the eve of the championships. 
The 11th seed, who ousted defending champion Rachael Grinham in the previous round, continued her 'giant-killing' run by taking out seventh-seeded compatriot Alison Waters 13-11 5-11 13-11 11-9.
"It really is unbelievable," said Botwright later. "The people you have to beat to get this far makes it so hard. 
"But I think the scoring changed just in time for me!"
In an extraordinary match later in the day, Ireland's 14th seed Madeline Perry showed the guts that took her to six in the world over two years ago when she fought back from two games and 9-7 down to beat unseeded New Zealander Jaclyn Hawkes 6-11 5-11 11-9 12-10 11-9 in 66 minutes.
Hawkes, who had arrived in the first major quarter-final of her career after a shock defeat of fourth seed Natalie Grainger in the previous round, failed to convert match balls from 10-5 in the fourth.
"It was pure determination, I guess," said the jubilant 31-year-old from near Belfast in Northern Ireland. "But I really felt uncomfortable out there - probably because I knew I had such a good opportunity."
14th seed Perry is fighting back up the rankings after suffering a serious head injury in a mugging attack in Milan exactly a year ago.
"What I went through last year got me through that match. I nearly died then. I was told I'd never be able to concentrate.
"I don't think I've ever made a come back like that," said the world No16.
Perry will now take on Nicol David, the world number one from Malaysia who recovered from 5-8 down in the first game to beat Egyptian rival Omneya Abdel Kawy 11-8, 11-1, 11-9.
[1] Nicol David (MAS) bt [9] Omneya Abdel Kawy (EGY) 11-8, 11-1, 11-9
[14] Madeline Perry (IRL) bt Jaclyn Hawkes (NZL) 6-11, 5-11, 11-9, 12-10, 11-9
[5] Jenny Duncalf (ENG) bt [3] Natalie Grinham (NED) 11-8, 10-12, 5-11, 11-6, 11-7
[11] Vicky Botwright (ENG) bt [7] Alison Waters (ENG) 13-11, 5-11, 13-11, 11-9
Issued by iSPORTmedia

It was 13th time lucky for England's Jenny Duncalf in the women's quarter-finals of the Hi-Tec World Open Squash Championships when the World No.5 from Yorkshire upset Dutch star Natalie Grinham to ensure the event's first English finalist for five years.