Waites was trailing 2-0 before he produced an outrageous comeback to knock out the top seed 4-2.
He will now face Scott Mitchell in the semi-finals after he whitewashedMichael Unteruchner in their quarter-final clash.
Elsewhere Dutchman Chris Landman came from three sets to one down to knock out crowd favourite Ben Hazel.
The man nicknamed ‘Mr Ben’ has quickly become one of the more popular unseeded players at this year’s tournament and he was on the precipice of making it through to the quarter-finals as he got into a 3-1 lead.
Landman dug deep however and quickly replied to get back to level and then managed to take the decider.
He will face Wayne Warren in the quarter-finals after the Welshman hammered Andy Hamilton 4-1 in the earlier match on the men’s side of the draw.
Meanwhile in the women’s side of the draw last year’s runner-up Lorraine Winstanley whitewashed Casey Gallagher 2-0.
Winstanley, who fell to Mikuru Suzuki in the final last year, will now face Lisa Ashton for a place in the final four.