Selby held off a stirring fightback from his opponent in the final session to join John Higgins as a four-time champion, punching the air after sinking the final black under immense pressure.
The 37-year-old had endured a torrid time after winning his previous crown in 2017, crashing out in the first round as defending champion and surrendering his status as world number one after going over two and a half years without a British-based ranking title.
But talk of the Leicester man’s demise proved premature as he chiselled his way back towards the top, culminating in a dazzling return to top form this fortnight, in which he lost just 11 frames over his first three matches.
Selby strode out for the final session with a 14-11 advantage, but well aware of the danger posed by Murphy, who had roared into the final in the kind of free-flowing form that evoked memories of his charge to the title as a fresh-faced qualifier in 2005.
By his own admission, Murphy had endured a dismal season under lockdown, complicated by travel restrictions from his home in Ireland, and conceded he had been as surprised as anyone to rediscover his game on the biggest stage.
But despite responding with back-to-back centuries when Selby stood one frame from victory, it proved to be a case of what might have been for Murphy, who missed two earlier opportunities to cut Selby’s advantage to a single frame.
Resuming 10-7 behind on the final day, Murphy won the opener but left the black dangling over the pocket in the next, hastening what appeared to be the decisive move from Selby, who responded with the first century of the final as he went on to stretch his advantage to four frames.
But just as in his semi-final, when he reeled off the last eight frames to beat Kyren Wilson, Murphy raised his game with his back against the wall, a superb 100 bringing him back to 13-10, and a brilliant long red helping him over the line in the next.
The fist-pump with which Murphy greeted his reduction in arrears proved premature, as Selby gleefully swept up a long red from Murphy’s poor break-off in the next frame, and his subsequent 62 ultimately proved enough to leave the Leicester man in full control.
It was the same story at the start of the evening session, which Murphy began with a spectacular long red, only to then fluff the simplest of pinks to the middle, leaving Selby to fire a 66 and move within three frames of victory at 15-11.
The pair split the two subsequent frames, then a brave 58 from Murphy sent him in for the final mid-session interval still harbouring a glimmer of hope at 16-13.
Selby had other ideas, delivering his second century of the final with a faultless 120 to move within one frame of victory.
However, Murphy threatened one final twist as he responded with back-to-back century breaks of 100 and 103 to reduce the deficit to 17-15 and raise the prospect of a remarkable fightback.
He came close to taking another after Selby broke down on a break of 38 in the next, but a difficult red down the cushion proved a step too far, and Selby duly cleared up to go shoulder-to-shoulder with Higgins on the all-time list.