Neil Robertson is through to the last four of the Masters after a 6-4 quarter-final win over Mark Williams at Alexandra Palace.
A break of 95 gave the Australian a 3-1 interval lead, which he extended to 4-1 after the break.
The Welshman fought back to 4-3, but Robertson moved to within one frame of victory with a 119 clearance.
Williams won the next two, only to miss a black in the 11th that let Robertson book a meeting with Judd Trump.
It was fitting that a Williams mistake gave Robertson the chance to seal his passage to the last four, the world number two having put in a display littered with errors, for which he was punished.
In the scrappy, near 40-minute first frame, and again in the third, fifth and eighth, Williams made basic errors and was made to pay by Robertson, who overcame damage to his cue tip to book a first Masters semi-final after three previous quarter-final defeats.
"I potted some really good balls under pressure to go 5-3 up," said Robertson. "From there you expect to have once decent chance to win the match.
"I miscued in practice and [the cue tip] flared up. We tried to repair it as best we could. I'll have to change it tonight.
"You're meant to play in a few cue tips to get them ready in case this happens, but I haven't done that. I'll have to get in a couple of hours' practice to play it in."
After a forgettable first frame, Williams levelled with a break of 78 before Robertson opened up a lead that he would ultimately not relinquish.
The world number five won the third on the final black after Williams missed a straight yellow, then triumphed either side of the interval to go within two frames of victory.
Williams, a two-time Masters champion, took advantage of a touching ball to use the black to pot a red on the way to winning the sixth and further reduced the gap with a run of 68 in the seventh.
Robertson's brilliant clearance in the eighth put him on the brink of victory and, although Williams was able to prolong the match with the help of a 78 in the ninth, a final, fatal error in the 11th sealed his fate.
