Selby toppled Murphy 18-15 in a pulsating Monday night climax after delivering a characteristically gutsy display in front of a raucous capacity crowd.
Only Stephen Hendry Steve Davis, Ronnie O’Sullivan and John Higgins had won four world crowns at the Crucible and Selby catapulted himself into their elite green baize club after a nervy finale.
Selby had opened up a 17-13 lead to put himself on the brink but Murphy, world champion in 2005, rattled off consecutive century breaks to halt the world No.4’s hopes.
But Selby held his nerve to clear up in the 33rd frame and etch his name further into World Championship folklore.
With the storied South Yorkshire venue sold-out for the Bank Holiday Monday bonanza, world No.7 Murphy had sent them into raptures during the afternoon as successive breaks of 100 and 56 pegged Selby back.
The crowd firmly threw their weight behind the 2005 champion but Selby, 37, showed exactly why he’s a 19-time ranking event winner with a granite performance under pressure.
The ‘Jester from Leicester’ went into the evening session with a three-frame lead after bolstering five fifty-plus visits in the penultimate session with a brilliant break of 107.
Selby knocked in visits of 62, 54, 50, 62 and 69 on Monday afternoon as Murphy, 38, was left with considerable work to do.
He rallied to take the 23rd and 24th frames but Selby, chasing a maiden Triple Crown title since his Crucible triumph four years ago, repelled ‘Magician’ Murphy’s box of tricks to go into the evening in the driving seat.
The atmosphere inside the old venue was electric when the players returned but despite the crowd getting firmly behind Murphy, it was Selby who extended his lead in the session’s first frame.
He rolled in a typically gutsy break of 66 to place him three frames from victory and leave Murphy, playing in his fourth World Championship final, with a mountain to climb.
Back came the nine-time ranking event winner in the second frame of the night, however, as a haul of 73 points reduced the arrears to three frames once more.But the pendulum swung once more in the 28th frame of the marathon contest as Selby, an eight-time major champion, held himself together to make a crucial break of 68 and regain his four-frame lead.
A see-saw contest was developing under the Monday night lights and it was Murphy who struck next, preventing Selby from moving to within one frame of victory with an important visit of 58.
Both players returned from the mid-session interval to that famous roar once again and it was Selby, European Masters and Scottish Open champion this season, who extended his advantage straight after the break.
He rolled in a brilliant 120 clearance to place him just a single frame from victory and emulating his Crucible hegemony of 2014, 2016 and 2017.
Resilient Murphy rallied, however, celebrating wildly after reeling off consecutive frames to make the score 17-15 and give the Leicester potter finish line jitters.
But Selby held his nerve after Murphy gambled on taking a tight red down the cushion to haul himself over the line – and follow in Hendry, Davis, O’Sullivan and Higgins’ glittering baize footsteps.