UK Snooker Championship 2013: Selby makes 100th 147 break
Mark Selby made the 100th 147 break in the history of professional snooker on his way to beating Ricky Walden 9-5 in his UK Championship semi-final.
Defending champion Selby, 30, led 4-2 at the time in the best-of-17 match.
He lost position after potting the final pink but managed to roll the black into the middle pocket to complete his second maximum clearance.
Selby can reclaim the world number one ranking from Neil Robertson if he beats the Australian in Sunday's final.
Englishman Selby looked to be cruising at 6-2 up at the interval, despite not playing at his best, and edged to within a frame of victory by winning the first two on resumption as Walden missed a host of regulation pots.
But Walden finally found some form with a break of 50 to end a losing run of five frames and followed that up with a 62 in the next to make it 8-4.
Selby looked to have the match won when he reached 58, but an error let Walden back onto the table and the 31-year-old won his third straight frame with a superb clearance of 85.
However his run came to an end as Selby hit a sparkling century to seal the match at the fourth time of asking.
"I didn't think I played fantastic at all," Selby told BBC Sport. "The 147 came out of nowhere. I was struggling.
"Ricky had chances but he didn't take them and I was just picking up the pieces.
"I probably played at 50-60% and missed balls with some amateurish play. I don't know why, perhaps it was about concentration, but I can't afford to make those mistakes against Neil."
Steve Davis made the first competitive 147 in 1982, while Ronnie O'Sullivan and Stephen Hendry have both made 11 during their careers.
Selby will pocket £55,000 for his feat, in addition to the tournament's high break prize of £4,000, as long as nobody else makes a perfect clearance.
The Leicester player made his first 147 at the Jiangsu Classic in China in 2009.
Earlier this year he missed the final black of an attempted maximum clearance in the second round of the China Open.
Selby, who needed a brilliant shot on the brown to get down for the blue during his 147, admitted that the memory of that miss in China had gone through his mind as he got towards the sharp end of his record break.
"It did, once I ran out of position on the green," he added. "Then when I potted pink, I automatically thought I'd be on black so when I wasn't I thought to myself, 'Oh not again,' but thankfully I potted it.
"To do it in a big tournament like the UK makes it a special moment."
Looking ahead to Sunday's final against Robertson, who held off an impressive fightback from Stuart Bingham on Friday to progress, Selby said: "Neil is a great player, he's number one.
"He's been so consistent over the last two years. It'll be a tough game so I'll need to perform better than I have done."