Ronnie O'Sullivan needs five centuries to squeak past Mark Williams

Ronnie O'Sullivan rattled in five centuries but still needed to win a last-frame decider to beat old rival Mark Williams at the Cazoo Tour Championship.

O’Sullivan, set to climb to number one in the world for the fifth time in his career ahead of next month’s World Championship, won 10-9 in Llandudno to set up a semi-final showdown with Neil Robertson on Friday.

Breaks of 131, 128 and 97 helped the six-time world champion into a 5-3 lead at the end of the afternoon session.

Welshman Williams hit back in the first frame of the evening with a 103 break before O’Sullivan responded with 100 to lead 7-5 at the mid-session interval.

Williams, a three-time Crucible champ, dug in to pinch two scrappy frames and level the match, but he then let O’Sullivan in for a clearance of 101 to move 8-7 up.

O’Sullivan was pegged back again but a clearance to the black of 127 put him one from victory before Williams hit back once more, with stunning pots on yellow and green taking it to a final frame.

Nerves set in for both players but O’Sullivan got over the line, clearing from the final red to pink to book his place in the last four.

Judd Trump faces Luca Brecel in tomorrow's concluding quarter-final, with the winner facing John Higgins on Saturday.