London: Mark Selby moved to the brink of the World Championship semi-finals on Tuesday after opening up a 12-4 lead over Alan McManus at the Crucible in Sheffield, northern England.

Leading 4-3 from the morning session of the last-eight tie, Selby won eight of the afternoon’s nine frames to close to within one frame of a place in the last four.

The 30-year-old, a runner-up in 2007, took control from the start of the session, with a break of 86 giving him the first frame before a missed brown from Scottish veteran McManus enabled him to go 6-3 up.

McManus finally got on the board when he made it 8-4, preventing Selby from sealing victory with a session to spare, but back-to-back breaks of 109 and 74 in frames 14 and 15 helped leave the Leicester cueman firmly in control.

Fifth century break

Barry Hawkins, the world number four, was also closing in on a second successive semi-final appearance after going 11-5 up in his last-eight encounter with Dominic Dale.

Meanwhile, defending champion Ronnie O’Sullivan brought up his fifth century break of the competition as he overcame the loss of the first two frames to go 6-2 up against Shaun Murphy.

Murphy produced a century break to claim the first frame and also took the second before O’Sullivan roared back, overcoming some erratic cuing to move 3-2 ahead.

The five-time champion then began to turn on the style, closing out the session with breaks of 94 and 136.

It was not such plain sailing for world number one Neil Robertson, however, who found himself 6-2 down after his first session against Judd Trump.

The Australian won the first frame, but Trump, a beaten finalist in 2011, rattled off the next five in succession to inch towards a place in the semi-finals.