"He has continued his advancement into the duathlon scene which is slightly harder than triathlons with a bit more running. Cairns is still finishing clear of competitors and narrowing the gap on seniors," Triathlon Hawke's Bay Sport development manager Brendon Lodge said.
Ken Maclaren coaches Cairns, who also is in the Tri New Zealand regional high-performance squad, and Ali Hollington mentors him in the youth squad.
Angela Hannah was the Open women's winner in a time of 1h 21m 25m. Sheryl Summers (vet 2) was second in 1h 27m 55s.
Another strong junior, Eva Goodisson, won the Peak Fitness event, completing the short course (2km run, 11km cycle, 2km run) in 39m 10s. Jane Heather-Sclater (vet 1) was runner-up in 39:30.
Junior Kairon was the quickest male, finishing in 45m 56s, in his first duathlon.
Karen Toulmin (open grade) won the The Hits Duathlon (4.5km run, 22km cycle, 4.5km run) in 1h 19m 58s and Kathy Eggers (vet 1) was second in 1h 26m 39s.