Reigning champion Ronnie O'Sullivan faces an uphill battle to stay in this year's World Snooker Championship after being outplayed by Anthony McGill in the second session of their second round match at the Crucible.
Two centuries underpinned a superb performance from McGill, who won the first four frames of the day to move 8-4 in front and will take a 10-6 advantage into Friday evening's conclusion of their best-of-25 clash.
O'Sullivan looked desperately out of sorts but rallied after the mid-session interval and gave himself some hope of a comeback as he took the final frame of the session with a quick-fire break of 69.
O'Sullivan adopted Mark Williams' controversial break-off technique with limited success and it was McGill, who had trailed 4-1 before winning the final three frames on Thursday to pull level, who started in style with a break of 71.
O'Sullivan would pot only 10 balls in the first half of the session and with his game woefully out of sorts McGill capitalised, with consecutive breaks of 47, 126 and 89 taking his streak to seven frames in succession over the six-time champion.
O'Sullivan rallied to reduce the deficit to 8-5 but McGill guaranteed the lead with a coolly-dispatched 105, before the pair shared the final two frames of an engrossing morning's play.