Twenty Wakatipu, Wanaka and Dunedin riders assembled at the starting line for the tight 2km course around the frost-covered lower paddocks through Remarkables Park Town Centre.
Riders completed 10 laps in the one-hour event, with the final 10 minutes signalled by the bell as the leader cycled past the post.
They contended with frozen mud, a water feature and barrier obstacles, as well as a morning temperature of 3degC.
In the men's round, who all completed 10 laps of the course, Tristan Rawlence, of Dunedin, came second in 1hr 4min and Brent Herdson, of Queenstown, was third in 1hr 5min.
The women completed nine laps of the course. Anja McDonald, of Dunedin, was first in 1hr 3min and Hannah Thorne, also of Dunedin, was second in 1hr 9min.
The series was hosted by the Queenstown Mountain Bike Club and is set to continue as part of the Queenstown Winter Festival on July 1 at 2pm at the same location.
About 60 cyclists are expected to compete for the national heat.
Registration costs $35.
Competitors from around New Zealand were anticipated, plus a special appearance by US rider Katie Compton, of Colorado Springs, ranked second in the world.
The overall winner will win one year's supply of One Square Meal products.
The mountain bike club was also raffling a $2800 cyclocross bike, to be drawn on July 1.
Raffle tickets cost $10.
