Villumsen won by 7:49 ahead of 22-year-old Sharlotte Lucas, with veteran Nelson cyclist Karen Fulton out-sprinting Emily Collins for third.
Track specialist Lauren Ellis made the first move when she opened a 40-second lead on the second of eight laps, setting up the target for her fellow New Zealand representatives Villumsen and Jaime Nielsen to chase.
The pair bridged up and overtook Ellis on the climb up Dyers Pass on lap three but Nielsen, who beat Villumsen in yesterday's time trial, withdrew suddenly from the efforts at the top of the climb on the next lap.
"I thought it was a bit early," Villumsen said. "I wanted her to get over the climb and work together for at least another lap or two. But I must have had pretty good legs today.
From that point Villumsen took complete control, extending her lead from three minutes on lap three and increasing the margin on every lap.
It was a complete master class from the cyclist who has won five world championship medals, was fifth in the Beijing Olympic road race and fifth at the Commonwealth Games in Glasgow.
"It's great to have the national jersey to wear for my new team this year. We have kept it in the family because Rushlee (Buchanan) won it last year and she is my teammate."