The 21-year-old Wanaka athlete finished the Race the Train 12km in 38min 9sec, well ahead of the train's time of nearly an hour.
Despite the sizable lead, Insker-Baynes said this year was a lot tougher because of the faster competitors.
An achilles tendon injury four months ago meant the week immediately before Race the Train event was his first ''100km week in a long time''.
Having matched Inkster-Baynes for 8km of the race, second placegetter Daniel Balchin, originally from Dunedin, said finishing within a minute of Inkster-Baynes
was ''not too bad''as he had raced the Lovelock Mile in Timaru on Saturday, where he also finished second - by 0.06 seconds.
His legs were ''feeling it today'' but he just ''could not resist'' giving Inkster-Baynes a bit of competition and running the unusual race.
With clear skies and the mercury in the mid-20s, Balchin said it was ''pretty hot out there''. Thijs Hubber was third man home.
Olympic triathlete Nicky Samuels (Wanaka) surprised herself when she won the women's ' 12km race, coming home ahead of Joanne Saxton and Renee Saxton.
The race featured a 5km and 12km division in which competitors raced parallel to the train in a bid to beat the locomotive.
Organiser Adrian Bailey, of Active QT, said about 300 competitors raced, down a little on the inaugural race last year due to the Kingston Flyer being out of action for almost a month.
Inspiration for the event was drawn from the original Race the Train in Wales, Mr Bailey's home country, and he expects the race to grow in popularity.
