Cwm's Williams was strongly fancied to set up a clash with fellow multiple World Champion Higgins, but was denied by underdog Woollaston - who had never previously been beyond the quarter-finals of a ranking event - in a dramatic contest. Leicester's 27-year-old Woollaston will go into tomorrow's best-of-17 final believing he can go all the way to the £60,000 top prize.
His other highlights include winning a Players Tour Championship event in 2011 and making his first official 147 at the recent Lisbon Open. But this has undoubtedly been a career-best week for Woollaston. He has been supported throughout by Belarusian wife Tatiana, who also achieved a landmark earlier in the week by refereeing a televised ranking event match for the first time.
Woollaston settled immediately with a break of 82 to win the opening frame. Williams had a chance to level but missed the final yellow in frame two and his opponent made an excellent clearance which included a thumping green down the side cushion.
Williams took a scrappy third before Woollaston's 75 made it 3-1 at the interval. Back came Williams with a break of 88 to win frame five, and when Woollaston missed a tough penultimate red to a baulk corner in the sixth, the Welshman cleared for 3-3.
Woollaston regained the lead with a superb break of 90, and took the next in two scoring visits for 5-3. He started to show signs of tension in the ninth, missing several pots as Williams halved the deficit. Frame ten came down to a safety battle on the colours and Williams was trapped in a near-impossible snooker. From the chance that followed, Woollaston potted yellow and green, but missed a tricky brown to a baulk corner, and Williams cleared for 5-5.
A cracking long red early in the decider set Woollaston up for a break of 30. He missed a tricky mid-range to a top corner, but Williams immediately failed on a red to a centre pocket, and Woollaston seized his next chance with a run of 60.
"I was proud of the way I held myself together in the last frame, after I had messed up the chance to win 6-4," said Woollaston. "Mark didn't play his best, which was lucky for me. I played well from 3-3 to 5-3, and then felt the pressure after that. It's amazing to get to the final, the best thing that has happened to me in snooker.
"John Higgins has always been my favourite player - he won the World title the first time I watched it in 1998. But I want to beat him tomorrow. When I'm practising in the club I dream of playing in a final against one of the top players. That will become reality tomorrow. At times that dream felt miles away, although I have always believed I could do it."
The final starts at 1pm, with the concluding session at 7pm.
