The 23.5km women's course suited her technically and so did the gusty northwesterlies which demanded constant mental application, especially around corners - unlike the straight course in Christchurch.
"It's the first time trial [win] for me so it was pretty special to be able to get the No 3," Buchanan said after adding the short discipline to her previous national criterium and road-race crowns.
However, the two-time (2010, 2014) national road-race champ was not preoccupied with backing the time-trial bragging rights with a road-race victory today in the women's elite 117km grind, after her UnitedHealthcare teammate and defending champion Linda Villumsen withdrew this week.
"That's what we do all year so for me it's better to just smash it out next day rather than go down and then have to come back up," she said, emphasising there were only 10 of them in the field yesterday but there will be 30 today with a lot more fresh legs.
She saw the time trials as a "good hit up" in soothing the nerves a little and getting the legs going before the road race.
"We'll see what we've got left in the legs for tomorrow," a beaming Rushlee said after collecting her medal on the podium.
It was a false start for Buchanan and Marlborough's Georgia Cattrick in yesterday's time-trial when marshals pointed them in the wrong direction at the first turn off but she kept cool.
"It was a mishap but in the moment you just have to stay calm, conserving your energy levels and refocusing on starting again so you can turn everything to your advantage to turn things around."
She will proudly wear her silver fern jersey at every time trial now, including during her stint to the United States in April.
"It's definitely an honour and something I've never had."
Nielsen, saluting a fantastic course, said it would have been nice to nail a treble but it came down to a couple of seconds.
"[Napier] has a little bit more texture and is a lot more fun because you're not just sitting there thinking about how much you're hurting but what's coming up on the course next," said the 30-year-old, mindful of hindsight but aware she came in quite strongly so perhaps she could have done a little more in between.
"Everyone can look back at their race and say they could have done things differently."