Around 14 children were at the startline in the 6 & Under grade, who were given extra guidance from experienced triathlete James Wright leading them on his bike around the first 500m run, then the 1km bike back down towards the Kowhai playground, and the final 500m run at the northern end again.
As the smallest of the bunch, the cycles on show ranged from BMX to even a push bike.
Having already run in some adult multisport events with his father, though not always completing them, 6-year-old Dargen Wood led from virtually start to finish, completing the lot in 10 minutes, 16 seconds.
Wood, who then went back to cheer on his sister in finishing the same race, said he likes to compete to meet friends.
Still, he had to admit he was "quite excited" to see the finishing line with no-one ahead of him.
Around 10 minutes after the little ones' departure it was the turn of the 15 entrants in the 8 & Under grade, where mountain biker Jorden Pike lived up to his pre-race visualisations.
"That I was going to win this," Pike said was on his mind.
He was pleased his transitions from both bike and clothing items went well, as he finished another clear winner in 16 minutes, 46 seconds for the two-lap 1km run, 3km bike and 500m run to finish.
Pike enters a lot of bike racing events as his family is heavily involved with the Wanganui Mountain Bike Club, so multisport events were a fun way to prepare for those.
"You are training for something. I'm just training."
Te Mana Kaua, 11, had a lot of work to do to see off 20 other children in the highly competitive 11 & Under grade.
Unlike Wood and Pike, he had to come from behind to catch the two leaders on the last running leg to win in 26 minutes, 20 seconds.
"One of them stopped and I sprinted with the other," Kaua said.
He had recently won another duathlon which helped with his experience.
"It's fun. I just get out there and see what I come up with."
Club spokeswoman Melina Holmes said while around 50 kids was a comparable number to last year's inaugural Kids Duathlon, organisers still want to grow the event, which has now been included on the regular events calender.
"We want the whole of Wanganui to bring their kids.
"Every kid that's come along has had a really good time, we just need more kids to come along and have a good time.
Every entrant received a certificate while they could also enter the draw for a new bike.
The club's activities continue this month with the 5one5 triathlon on Saturday, November 23.