A ruthless Judd Trump produced three centuries in the space of five frames as he took command of his World Championship quarter-final against Stephen Maguire in Sheffield.
Trump began with a clearance of 131 and added breaks of 67, 106, 78 and 101 to race into a 5-0 lead against a shell-shocked Maguire, who potted just seven balls and accrued a total of 24 points in the first five frames.
After winning the last six frames in a row to beat Ding Junhui in round two, Trump extended his unbeaten run to 12 by clearing the remaining colours when Maguire missed a tough brown to the yellow pocket in frame six.
Maguire, who had survived final-frame deciders in both the first and second rounds, finally got on the scoreboard in the next but missed another crucial brown in frame eight and Trump made the most of his chance to secure a 7-1 overnight lead.
The second session gets under way on Wednesday afternoon and Trump needs six more frames to reach the semi-finals with a session to spare.
Gary Wilson had earlier reeled off five frames in succession to gain the upper hand against Ali Carter, while Kyren Wilson and David Gilbert were locked together at 4-4 after the opening session of their quarter-final.
A total clearance of 135 had helped Carter race into a 3-0 lead and extended his streak of frames won to nine, the two-time Crucible runner-up having taken six in a row to beat Zhou Yuelong 13-9 on Monday.
The same quality was largely absent in the day’s second quarter-final, with Kyren Wilson managing a highest break of just 46 in the first eight frames against Gilbert.
Kyren Wilson, who had produced centuries in the last two frames to beat Barry Hawkins 13-11 in round two, somehow scrapped his way into a 4-3 lead before Gilbert, who had earlier made breaks of 68 and 60, saved the best until last with a 109 clearance to level at 4-4.
Both matches resume at 7pm on Tuesday before playing to a finish on Wednesday.
In the remaining quarter-final, four-time champion John Higgins dug deep to end the opening session level at 4-4 against 2010 winner Neil Robertson.
Breaks of 58 and 91 helped Robertson into a 3-1 lead but Higgins displayed his characteristic tenacity to reduce his deficit by winning a 56-minute fifth frame.
Robertson won the next to restore his two-frame advantage, after which the cushions were cleaned following complaints from both players about some inconsistent bounces.
And although one such bounce saw Higgins run out of position on a break of 28, he won the seventh frame and produced his highest break of the match, 73, to claim the eighth as well.