Surfing in six-to-eight foot (two-to-two-and-a-half metres) waves at Cloudbreak, wildcard Coleborn grabbed single-wave scores of 9.27 and 8.10 for the day’s highest heat total of 17.37 out of a possible 20 to best Slater and compatriot Kai Otton in the non-elimination round one clash.
“The heat ended up good but the start was a nightmare,” Coleborn said. “Then I got that one nine-something and it really turned the head around for me.
“I still needed a score though and bagged another solid one at the end. I guess I got a couple of waves between all of the beatings I took.
“Out there on the ledge there are chip shots and you’ve got to be right there under them. That last one was a dream come true. It’s a different thing coming here compared to other contests.
“You knew a swell was coming and it’s Fiji and you just can’t think a bad thought. I’m happy to be here.”
South African Jordy Smith opened the event with a nine-point score after a late drop into a deep backhand barrel, on his way to securing victory over Hawaii’s Fredrick Patacchia and Californian Brett Simpson.
“It was pretty hard out there at first and I’m stoked that I caught two quick ones,” the 24-year-old said.
“On that one nine, it just opened up real perfect. I lucked into it on the way back out when the boys got stuck inside and it just held open and I came out and got a couple of turns in.
“I’m pumped. It’s my first time back to Cloudbreak since my rookie year and I couldn’t have had a better start. It felt fun out there and the waves are just pumping.”
Current world number one Joel Parkinson put in a solid performance to join Coleborn in advancing directly to the third round, with a heat win over Brazil’s Raoni Monteiro and local Isei Tokovu.
“The second half of the heat was really good,” Parkinson said. “The start was washing through and I thought it was going to be a scrappy one but it really turned on.”
John John Florence also booked his place in the third round, recovering from flu in time to secure a come-from-behind win over Brazilian Miguel Pupo and Australian veteran Kieren Perrow.