In the second semi-final of the day Madeline Perry from Northern Ireland defeated the fourth seed from England 10-12, 11-8, 11-7, 11-9.
After the match Madeline Perry commented "I wanted to play well after beating Nicol yesterday - it would have been disappointing to then lose in the semi-finals," said the 32-year-old world No8 from Banbridge, near Belfast.
"I was aware that Alison would come out fast and furious and I had to be up for it and work hard.
"Obviously beating the world number one boosts your confidence," added Perry. "I've beaten a few good players, but not a lot of world number ones!
"I am very proud of where I come from - so reaching the final of the British Open should put me up there with the best Northern Irish squash players."