Mark Selby and Shaun Murphy will meet in the Masters semi-finals after a dramatic day of action at Alexandra Palace.
Murphy saw off Marco Fu 6-4 before Selby battled from 5-3 down to beat John Higgins in a final-frame decider in the evening session.
The pair met in the 2012 quarter-final, won 6-2 by Murphy, though Selby won their UK Championship final that year and their 2007 World Championship semi-final.
The Leicester player had to work hard for his win here, but he led 3-1 at the mid-session interval after responding to Higgins' opening 58 with frame-winning breaks of 42, 70 and 98.
Higgins won a lengthy first frame back with a 43 break after Selby missed a red to the middle, and added a 69 break in the next to level at 3-3.
Selby led in the next after a 56 break but Higgins came back and won a high-quality safety battle on the black to take the frame and a 4-3 lead.
He extended that in the next, Selby desperately unlucky to fail with an escape from a snooker and concede a free ball.
Breaks of 48 and 61 saw Selby win frame nine and he scraped home in the next after Higgins potted a superb yellow but got a horrible kick on the green.
Higgins opened up a lead of 57 in the decider but missed a red, possibly attempting to turn it over with side spin after a poor positional shot. Selby responded by catching the pink to ruin his own position.
Selby laid a magnificent snooker behind the green and though Higgins escaped at the fourth attempt he opened up the reds, pink and black.
Selby was unlucky with a difficult positional shot off the brown and missed another cannon off the pink but after a tense frame, he produced a brilliant clearance including a spectacular double on the blue.