The pair were up against seven Australian competitors in the elite men's 37km race and crossed the line within 5sec of each other for the gold and silver medals.
Horgan (46.23.75) and Odlin (46.28.39) both ride for the Subway Pro Cycling team and will compete tomorrow in the 153km elite men's road race near Arthurs Point.
In January, Horgan finished second and Odlin first in the national time trial in Christchurch.
"The win means a lot. It's been a goal of mine since the start of the year," Horgan said.
"I've been training exclusively for it. I was buoyed by my performances at the elite nationals."
While he was happy to see his fellow Christchurch rider do well he said they had a good rivalry and motivated each other.
"The course was hard. That final climb was really testing. And the surface was quite dead and quite slow."
The in-form Horgan went into the event after winning the Tour of Canterbury last weekend including breaking Odlin's record for the 16km time trial.
The men's elite was the only category won by New Zealand.
The leading New Zealander in the elite women's time trial of 25km was Aucklander Georgia Williams, who finished fourth in her first major event in the elite ranks. Australians Shara Gillow, Gracie Elvin and Bridie O'Donnell filled the medals.
There were no medals handed out to New Zealand riders in the under-23 section although Jason Christie, of Mid South Canterbury, was fourth.
Nick Bain, of Auckland, was second in the men's under 19 25km time trial won by Australia's Alexander Morgan, while the New Zealand under-19 women did not feature in a trial dominated by Australian cyclists.
Former track world champion Hayden Godfrey said he was pleased with the effort of both Horgan and Odlin.
"It could have been either of them on the day. They were never more than 10 seconds apart in time checks ... Both came down wanting a medal, preferring a gold one, and [for them] to get first and second is a fantastic result."
Attention turns to the road races with the under-19 and elite women today and the under-19, under-23 and elite men tomorrow.
