It was a champagne moment for Royals captain Murty, who ended a five-year goal drought with his cooly-struck spot-kick.
The right-back had previously been the only regular outfield player without a goal this season and had been granted permission to take penalties and free-kicks and push forward at every opportunity in a bid to end his scoring drought.
Minutes later, Murty enjoyed another champagne moment as he walked up to lift the Football League Championship trophy with the rest of the squad.
But QPR so nearly put a dampener on the celebrations as they carved out enough chances to deny Reading the win they so desperately wanted to finish with.
Paul Furlong cancelled out Dave Kitson's opener and Gary Waddock's side had plenty of other chances as they looked to attack from the start.
In a first half of few chances, Kitson broke the deadlock five minutes before half-time when he finished off from close range after a sweeping Reading move.
Goalkeeper Marcus Hahnemann bowled the ball out to Bobby Convey and the winger traded passes with Nicky Shorey and floated over an inviting far-post cross.
John Oster got on the end of the cross and did well to sidefoot the ball back into the path of Kitson, who had the simplest of finishes.
Reading had chances to make the game safe and go in search of the three goals they needed to become the first team to secure a double century of points and goal in a single season.
Kitson nearly added a second when he spun to collect a clever pass from Murty, only for substitute keeper Jake Cole to bravely save at his feet.
Cole then sprinted from his penalty area to deny Kevin Doyle as the Irish striker ran clear midway through the second half, but QPR hit back with a sustained spell of second-half pressure.
Furlong levelled when he swept home from substitute Ray Jones' neat knock down.
And Defender Dan Shittu slammed a shot into the sidenetting as Rangers went for their first win in 11 games in an attempt to spoil the Reading party.
But the Royals hit back with one final push.
Convey volleyed into the sidenetting and substitute Stephen Hunt saw a spectacular overhead kick tipped over by Cole, before Murty provided a fairytale finish.