Three-time victor Mark Williams held disconnected a spirited John Higgins fightback to triumph a Crucible classical 13-12 connected nan achromatic arsenic he reached nan semi-finals of nan World Championship.
Resuming astatine 8-8 connected Wednesday, Higgins was initially near to rue costly misses successful each of nan first 4 frames arsenic victor Williams reeled disconnected each 4 pinch 3 half-centuries on nan way.
Williams, 50, who had trailed 5-1, took nan 20th framework but was past mostly confined to his chair arsenic four-time champion Higgins delivered a stirring consequence from 12-8 down.
The 49-year-old, who appeared to beryllium labouring, abruptly recovered his hit and compiled breaks of 94, 114 and 67 to group up a melodramatic finale.
Both players had opportunities to clinch a tense last framework but erstwhile Higgins rattled nan jaws of nan area pouch connected nan blue, nan Welshman capitalised to go nan oldest subordinate to scope nan past 4 since 52-year-old Ray Reardon successful 1985.
Williams' triumph complete Higgins intends he will look Luca Brecel aliases world number 1 Judd Trump successful nan semi-finals.
In Wednesday morning's different quarter-final Ronnie O'Sullivan maintained his four-frame lead complete Si Jiahui and will return a 10-6 lead into nan concluding convention astatine 19:00 BST.
Leading 6-2 overnight, 'the Rocket' traded frames pinch world number 13 Si to caput into nan mid-session interval astatine 8-4.
O'Sullivan, who is bidding for a grounds eighth crown successful nan modern era, went 9-4 up erstwhile Si missed a reddish to nan near mediate erstwhile 43 points up pinch 43 remaining.
Despite that setback, nan 22-year-old from China, who had compiled a period successful nan 10th frame, took nan adjacent took pinch runs of 61 and 52.
O'Sullivan, though, showed each his acquisition to return nan 16th framework pinch a break of 64 to reconstruct a patient cushion.
It leaves nan Englishman connected people for a a record-extending 14th quality successful nan semis.