Campbell, who fills most of his weekends rowing and playing rugby for St Paul's Collegiate, ventured out early on Saturday morning, fly-fishing in waist-deep water around the western shallows of the lake.
"I was there at 5am in the morning and hooked up about 10mins later - I got that one in and then had nothing else for the rest of the day."
His solitary catch, however, was more than enough to win heaviest adult male and best condition factor - a measure of fatness - at the club prizegiving.
"We don't normally give out two prizes but we did in this case, just for the simple fact it was so big," said Lake Okareka Fishing Club spokesman Dean Foster.
"It was a whopper and, with all the locals hanging around watching it come in, no one could remember a bigger fish coming out of the lake."
Eastern Fish & Game officer Mark Sherburn said it was easily the biggest fish he'd heard of coming out of Lake Okareka too but it also illustrated the incredible opportunities in the region.
"Lake Okareka definitely isn't known for trophy trout but it just goes to show, if you're in the right place, anything can happen," he said. "You never know when you're going to strike it lucky."
Although streams such as the upper Ngongotaha, Utuhina and Waiteti are now closed to fishing because of winter spawning, along with boat fishing on lakes Tarawera, Okataina and Rotoiti, the lower sections of the Ngongotaha, Utuhina and Waiteti streams remain open.
Lakes like Rotorua, Okareka, Rerewhakaaitu, Rotoma, Rotoehu and the smaller Ngapouri and Okaro are all good options, while the stream mouths on Lake Rotorua are also fishable, especially the Ngongotaha and Waiteti mouths.
"Anglers should check the regulation booklet or contact Fish & Game if in doubt about where they can fish, or need any advice. We're only too happy to pass on some fishing tips," said Mr Sherburn.
Campbell has taken his trout to Rotorua taxidermist Ray Port to be mounted and hopes to carry on fishing these school holidays.
