The Australian notched the highest single wave score of the tournament with a 9.70 for a brutal combination of forehand carves on the long rights of Lowers.
"I thought there were going to be waves in that heat but there was so much waiting and trying to scrap into those little ones," Melling said. "I knew I had to turn it on against Damien (Hobgood). I’m just so glad that wave came through in that last 10 seconds."
Melling next faces compatriot Taj Burrow as he seeks to retain his place in next season's top 34.
Frenchman Jeremy Flores edged an epic battle with local boy Patrick Gudauskas to book his place in round three in a high scoring heat which he won 17.30 to 16.93 in the clean three-to-four foot waves on offer.
"Pat (Gudauskas) is an amazing air surfer and I was expecting him to do crazy airs," Flores said. "I didn’t want to fall into that game because I’m not really an air guy. I wanted to show a difference in my carving turns and mix it up a bit. I know the first guy I saw doing that under-the-lip turn was Andy (Irons). It’s just this one turn that I can do and I just stick to a few of my tricks whenever I need to do them or need a score."
Another Australian Joel Parkinson, John John Florence and Brett Simpson, both of the US, were among the other winners on the day.
Round two results:
Heat 1: Joel Parkinson (AUS) 15.83 def. Conner Coffin (USA) 10.73
Heat 2: John John Florence (HAW) 14.37 def. Evan Geiselman (USA) 13.93
Heat 3: Taylor Knox (USA) 12.16 def. Owen Wright (AUS) 10.60
Heat 4: Jeremy Flores (FRA) 17.63 def. Patrick Gudauskas (USA) 16.93
Heat 5: Julian Wilson (USA) 14.63 def. Jadson Andre (BRA) 14.27
Heat 6: Matt Wilkinson (AUS) 14.66 def. C.J. Hobgood (USA) 11.30
Heat 7: Heitor Alves (BRA) 14.50 def. Kolohe Andino (BRA) 14.33
Heat 8: Adam Melling (AUS) 17.30 def. Damien Hobgood (USA) 17.13
Heat 9: Travis Logie (ZAF) 12.93 def. Miguel Pupo (BRA) 11.77
Heat 10: Brett Simpson (USA) 15.83 def. Kieren Perrow (AUS) 12.70
Heat 11: Alejo Muniz (BRA) 16.30 def. Fredrick Patacchia (HAW) 15.90
Heat 12: Kai Otton (AUS) 16.50 def. Tiago Pires (PRT) 16.27
Round three match-ups:
Heat 1: Kelly Slater (USA) vs. Matt Wilkinson (AUS)
Heat 2: Julian Wilson (AUS) vs. Alejo Muniz (BRA)
Heat 3: Taj Burrow (AUS) vs. Adam Melling (AUS)
Heat 4: Jeremy Flores (FRA) vs. Kai Otton (AUS)
Heat 5: Heitor Alves (BRA) vs. Adrian Buchan (AUS)
Heat 6: Mick Fanning (AUS) vs. Dusty Payne (HAW)
Heat 7: Joel Parkinson (AUS) vs. Taylor Knox (USA)
Heat 8: Gabriel Medina (BRA) vs. Michel Bourez (PYF)
Heat 9: Josh Kerr (AUS) vs. Bede Durbidge (AUS)
Heat 10: Adriano de Souza (BRA) vs. Travis Logie (ZAF)
Heat 11: Jordy Smith (ZAF) vs. Brett Simpson (USA)
Heat 12: John John Florence (HAW) vs. Yadin Nicol (AUS)