"It really wasn't for the faint hearted. I found it such a challenge and definitely the hardest I have done to date," he said. "I was immediately met with a wall of heat, which I wasn't quite prepared for.
"It surprised me how hot the swim was, but luckily my performance didn't suffer because of that.
"I took a lead right off the swim and Rotorua prepared me well for the bike which was my strongest section."
The 17-year-old started with a 28m 51s swim, then 1h 55m 46s on the bike and finished with a 1h 04m 37s run.
"Running was the hardest part of the race, because the hills were very steep," Ryan said.
"I and most athletes had to walk up one of the hills which was out of this world."
With thewin Ryan also took the overall Asia-Pacific tour 15-19 divisional title after previously collecting two second place finishes at Xterra New Zealand and Xterra New South Wales earlier this year.
Ryan was delighted as it was the first year entering the annual tour and he now has sights set on winning gold at the Xterra World Championships in the U19 category - a one off annual event in Kapalua, Hawaii in October.
It will be the third year the talented athlete will compete in this event, after finishing third in 2014 and a "disappointing" seventh place last year.
"The event is known as a tropical roller-coaster ride through pineapple fields and forests, and it certainly won't be a holiday for me," said Ryan.
"I am aiming for the gold, and I feel very strong and fit at the moment.
"I had a bit of a nightmare last year, which I want to put right and that is really going to drive me on in training.
"To progress in this sport I need to be winning competitions like this, so everything will now be geared towards Hawaii."
Ryan is aiming to become a professional off road triathlete although may one day look to compete in the Olympics.
"Growing up in Rotorua has really helped me, because you can't really get a better place to train," he said.
"My main goal is to become a professional in the off road event but I may consider thinking about the Olympic path.
"At the moment I prefer the rougher terrain and bigger challenge of the off road but you never know.
"It would be a real dream to be at the Olympics one day."
Rotorua's Olly Shaw finished eighth in the pro field in the Malaysian event.