"Thailand time is five hours behind us so I was lucky it was a midday start today," van Kampen said.
Her nearest rival in the five-rider under-23 section was Hamilton's Madison Farrant with a time of 39m35s.
Van Kampen's next event in the nationals will be Sunday's 105km road race.
Although she is the elite women's defending champion in this event she is unsure whether the Ramblers team will aim for a title repeat for her.
"We've got a lot of strong girls. We'll have a team talk tomorrow and see what the plan is. It will be good to try retain it," van Kampen said.
After Sunday she will have a break before preparing for next season where her major focus will be the Hawke's Bay-hosted elite nationals in January.
"After that the plan is to head to Europe," she added.
Van Kampen was one of four Ramblers riders to win titles in tough windy conditions yesterday. Olympian Westley Gough won the men's elite 25km title with a time of 31m52s.
His nearest rival, Stratford's Michael Torckler, stopped the clock at 32m27s. Marg Porter did her bit for the Ramblers quest to win the top club again with victory in the women's masters 3 25km event with a time of 39m44s which was more than 2 minutes faster than the second placed Mireille Sitters of Counties.
The other Ramblers winner, Carol Bone, won her masters 7 division title unopposed.
Elite women's winner Sharlotte Lucas of Papanui recorded a time of 37m59s. The Ramblers other second placegetter, men's masters 1 rider Patrick Barry, recorded 34m32s for 25km, 11s slower than winner Mike Henton of Counties.
Hawke's Bay's multiple world champion Regan Gough, a cousin of Westley, didn't compete yesterday.