MARK WILLIAMS held off a superb fightback from fellow former winner John Higgins today to triumph in a last-frame decider and reach his eighth World Championship semi-final at the Crucible.

The veteran duo, who have won seven world titles between them, were locked at 8-8 at the end of their second session before Williams put himself on the brink by taking all four frames on today’s resumption.

Four-time champion Higgins, though, dug in following the mid-session interval with breaks of 94, 114 and 67 to force a decider, which Williams took after his opponent missed a tense blue on the top cushion to seal a 13-12 victory.

Williams, who had trailed 5-1 earlier in the match, made the most of some unforced errors from Higgins, 49, to edge in front and then extend his lead to 10-8.

A couple of half-century breaks from the Welshman, who claimed the last of his three world titles in 2018, saw him seemingly close in on victory at 12-8 heading into the interval.

However, having regrouped, Higgins clawed a frame back before firing in 94 to move within two.

Williams, 50, then gave away a careless foul after touching the blue with his trailing arm when he was leaning over to pot a long red with the rest.

Higgins made the most of the opportunity, digging in again to build a fine 114 break.

The Scot missed a frame-ball red along the bottom cushion after a break of 67 in the next but was still able to force a final-frame shootout.

With both men running out of position when looking set, the deciding frame turned into a safety battle before Higgins caught the bump on the middle pocket, which allowed Williams in to edge in front 56-52.

Higgins sunk a red with the rest after Williams missed a tricky long red, then rolled the brown in on the top cushion only to miss the blue.

Williams clipped it in before finishing off the pink and black to seal a dramatic 74-69 victory.