The 31-year-old from Harrogate looked on course to reach her fifth final in the event after a strong start at the National Squash Centre in Manchester against the defending champion, but couldn’t maintain her momentum and eventually lost out 5-11, 11-6, 11-2, 12-10 after an entertaining hour.
After seeing Waters dominate the second and third games, Duncalf rallied in the fourth and had two game points to take it into a fifth. But her opponent rattled off the next four points to clinch victory.
As expected, Duncalf - a winner in 2007 and 2009 as well as runner-up in 2010 and 2011 - had enjoyed comfortable victories in the two earlier rounds, but always knew the real tests would come in the semi-final onwards.
But after a disappointing start to the year which has seen her hindered by niggling injuries which no doubt contributed to first round exits in the two WSA world tour events in the USA, the 31-year-old said she was pleased to have got through three matches in as many days.
“I feel a lot better physically than I did a week ago,” said Duncalf. “I’ve had a couple of little niggles so I was slightly concerned about playing. My preparation hasn’t been ideal for this event, but at least I’m playing and I’ve played three matches on the trot.
Watch Jenny Duncalf’s post-match interview by clicking the play button at the top of this page
“Physically, I’d like to be a lot fitter but at least I’m not injured.
“I started well and felt good. Tactically I managed to impose what I was trying to do, but I wasn’t able to continue that unfortunately.
“Every player is different, so there are different challenges with Alison, but she’s similar to any top 10 player - she’s a good athlete, she’s physically strong. She’s a great player and I knew I was going to have to play at my best to beat her.”
Second seed Waters, also a winner in 2008 and when beating Duncalf two years later, now meets Ireland’s Madeleine Perry in Sunday’s final after she caused a slight upset in the other semi-final by defeating favourite and two-time winner Laura Massaro 6-11, 12-10, 11-9, 11-6.
“Jenny played really well,” said Waters. “She came out firing and really put me on the back foot at the start. In the second and third I knew I had to try to step up, volley more and put her under pressure, but then in the fourth she came back again.
“At 10-8 down I told myself I really didn’t want a fifth, so really pushed to finish it off there and then.”