Mick Fanning and Connor O'Leary have wrapped up the day-four action at the Rio Pro with an all-Australian showdown.
Needing 5.68 on his final wave Fanning, a two-time winner in Brazil, obliged with a 7.17 for the highest score of the fifth and final heat.
Neither man laid down a marker during the first half of the allotted 30 minutes before Murray's 6.50 on his sixth wave.
Fanning, yet to place in the top three on tour this year, said he was relishing the lack of pressure.
"At the moment I'm just having fun with it," he said.
"I've never had a year where I've just been relaxed, I've always been chasing world titles and so on but it's good to just go out and do my best."
Fanning joined Joel Parkinson in the fourth round. The 36-year-old continued a strong day for Australia with a solid victory over Frenchman Jeremy Flores.
Parkinson - the 2012 world champion and four-time runner-up - grew into the heat, easing his way into proceedings before improving with each of his four final waves to post 6.93 and 8.50.
The veteran paid tribute to his opponent on a picture-perfect day at Saquarema.
"That's always my hardest round I find, I stumble worst there," he said.
"I had a very bad heat in Western Australia against Jeremy. I just wanted to change the rhythm of the heat because when he gets on a roll he's unstoppable."
Hometown hero Gabriel Medina was too good for Australia's Bede Durbidge. The third heat of the third round saw the 2008 Rio winner require a 6.77 to progress but he was unable to find a wave.
Earlier, Brazil's Wiggolly Dantas upstaged countryman and 2015 world champion Adriano de Souza with a dominant heat win over Hawaii's Sebastian Zietz.
Dantas posted 9 and 9.27 with his second and fourth waves for an imposing score of 18.27.
De Souza was first in the water for the third round, defeating compatriot Ian Gouveia with a top score of 8.50.
