Saturday 21 February 2015 13:03, UK
Belgium's 19-year-old rising star Luca Brecel and Leicester's Ben Woollaston both made it through to their first ranking event semi-final at the Welsh Open.
Brecel followed up his victory against world champion Mark Selby by upsetting world No 9 Walden, the highest ranked player in the quarter-finals, 5-3.
Meanwhile, 27-year-old Woollaston came from 2-1 down to win four frames in a row against Gary Wilson to reach the last four.
Highly-rated teenager Brecel will meet John Higgins for a place in the final after the four-time world champion, who is without a ranking title since the 2012 Shanghai Masters, hammered fellow Scot Stephen Maguire 5-1.
A couple of months ago I would have lost that match. Now I'm much more confident in my own ability and when I get chances I feel I'm going to take them.
"It's a dream to get to the semi-finals, I still can't believe it," world No 66 Brecel told the official World Snooker website.
"It was tough at the beginning as I wasn't relaxed. but once I had won my first frame I felt it would be tough for him to win another one because I felt so confident. When I'm behind I seem to find my best form, I've done that a lot of times in my career.
"A couple of months ago I would have lost that match. Now I'm much more confident in my own ability and when I get chances I feel I'm going to take them."
Woollaston will take on former double world champion Mark Williams for a place in the final at the Motorpoint Arena in Cardiff.
The 39-year-old Welsh potting machine has rediscovered his best form and easily dispatched Marco Fu 5-1.
Quarter-final results:
Ricky Walden (Eng) 3-5 Luca Brecel (Bel)
Ben Woollaston (Eng) 5-2 Gary Wilson (Eng)
Marco Fu (HK) 1-5 Mark Williams (Wal)
John Higgins (Sco) 5-1 Stephen Maguire (Sco)
Semi-finals:
(Best of 11 frames)
John Higgins (Sco) v Luca Brecel (Bel)
Mark Williams (Wal) v Ben Woollaston (Eng)
