Mark Selby moved to within one frame of a place in the semi-finals of the Dafabet World Snooker Championship after a dominant second session against Alan McManus at the Crucible Theatre.
Selby won eight of the session's nine frames to move from a 4-3 morning advantage to a 12-4 overnight lead in their best-of-25 last-eight clash.
The 2007 runner-up was in control from the start, producing a break of 86 in the opening frame of the evening before a missed brown from McManus allowed the Leicester man to move 6-3 ahead.
Selby continued to pick off frames until McManus finally got on the board to reduce the deficit to 8-4 and deny the Leicester man the chance of winning the match with a session to spare.
But the respite was temporary as Selby moved to another level to take the remaining four frames of the session including back-to-back breaks of 109 and 74 in the 14th and 15th frames respectively.
Barry Hawkins also stands on the verge of a second consecutive appearance in the semi-finals after taking control of his match against Dominic Dale.
World number four Hawkins seized on a series of errors by his opponent as he turned a 6-2 advantage after their morning session into an 11-5 overnight lead.
Dale must have hoped for better after taking the opening frame of the evening to reduce the deficit to three but Hawkins - who had compiled a break of 134 in the eighth frame - was soon back in command.
A missed pink by Dale allowed Hawkins in to go 7-3 in front and another mistake in the next saw Hawkins clear to pink to go five frames clear.
A missed black denied Hawkins a century break in the 12th frame as, like Selby, he looked set to win the match with a session to spare before gutsy Dale got the better of a safety exchange to claw back to 9-4.
Normal service resumed in the next as composed Hawkins produced a clearance of 88 to go 10-4 ahead, and although Dale pulled one back with a break of 53 a clearance of 67 by Hawkins in the last restored his six-frame advantage.
Earlier, defending champion Ronnie O'Sullivan recorded his fifth century-break of the tournament as he fought back from losing the opening two frames against Shaun Murphy to fashion a comfortable 6-2 lead.
Murphy got off to an ideal start as he recorded a century to take the first frame and then clinched the second before the five-times winner fought back in the third.
Both players were having problems as O'Sullivan failed to pot a red to the middle pocket and then followed the green in. He missed the brown moments later and it looked like things would not go his way before he eventually started to turn things around and finished off on the black to trail 2-1.
The Essex potter never looked back and took the lead for the first time in the match to go 3-2 up much to the pleasure of the Crucible crowd.
In the sixth frame, Murphy made a mistake as he left the black over the middle pocket and his opponent potted the pink and closed out the frame.
O'Sullivan then hit a quick-fire 94 to increase his advantage before eventually recording a break of 136 to finish the session.
World number one Neil Robertson, who won here in 2010, trails 6-2 after his opening session against Judd Trump.
The Australian took the first frame before losing the next five to his English opponent, who made it look easy as he recorded a century in the fifth frame.