Replay - Hendry hits 147 maximum
Seven-time champion Stephen Hendry trails Shaun Murphy 9-7 after the quarter-final second session, despite hitting a 147 seventh-frame break.
Murphy was 5-3 behind going into the evening session but started with a 137 break and never looked back, winning four straight frames.
The pair shared a series of tactical frames at the end of the session which left Murphy in control.
However Hendry's maximum break was the highlight of the day's play.
The Scot, 40, has now had nine maximums in his career, including one other in Sheffield in the 1995 semi-finals.
Providing no-one matches it, Hendry will earn £147,000 for the maximum and £10,000 for the highest break.
Frame seven's last black glanced both jaws before dropping into the pocket to the delight of the Crucible crowd.
World Championship 147s
1983: Cliff Thorburn v Terry Griffiths
1992: Jimmy White v Tony Drago
1995: Stephen Hendry v Jimmy White
1997: Ronnie O'Sullivan v Mick Price
2003: Ronnie O'Sullivan v Marco Fu
2005: Mark Williams v Robert Milkins
2008: Ronnie O'Sullivan v Mark Williams
2008: Ali Carter v Peter Ebdon
2009: Stephen Hendry v Shaun Murphy
After sinking a tricky pink with his penultimate shot, Hendry was left with an awkward cut back into the bottom corner to complete the clearance.
An anxious moment followed as the black briefly threatened to squirm free, before the crowd stood to acclaim the veteran.
The chance of a 147 came when a cannon off his fifth black opened up the pack and a pair of plant shots squeezed home to put the maximum within reach.
"It's a tremendous feeling and I'm absolutely delighted," said Hendry, who lost the last frame of the session to lead the best-of-25 match 5-3.
It is the ninth maximum in the history of the competition with Ronnie O'Sullivan and Ali Carter both achieving the feat last year.
Cliff Thorburn, Jimmy White and Mark Williams are the only other players to clinch perfect frames at the sport's greatest tournament.
"You have to grade maximums at the Crucible as the best because of the pressure of this venue," six-time champion Steve Davis told BBC Sport.
"Especially when you consider where the pack was at the start, Stephen is one of only two or three players who would have made that break, and from five reds out it was immaculate."
Currently ranked sixth in the world, Hendry has started the tournament well and managed a 140 break in defeating China's Ding Junhui in the previous round.
This season he has gone out of the UK Championship, the Masters and the Welsh Open at the first round, but throughout his illustrious career Hendry's World Championship performances have regularly outshone the rest of his season's form.
Stephen Hendry's first Crucible maximum
He reached a record 12th semi-final in last year's competition and reached the quarter-finals of the China Open earlier this month in the run-up to this year's event.
Hendry started the tournament as a 50-1 outsider to repeat his last triumph in 1999.
As well as seeing his odds fall to around 6-1, he has now become the oldest player to make a maximum in a world-ranking event.
However Murphy's form in the evening session left hendry in danger of slumping out of the competition
He raced through the frame following Hendry's maximum thanks to a break of 73, and when play resumed in the evening session Murphy began with runs of 137, 83, 104 and 80.
That run came to an end when the man who once won 29 consecutive World Championship matches pounced for the 13th frame, with a break of 51.
Murphy then won the scrappiest of frames to pull 8-6 in front before the pair traded the final two frames to end the day's play.