Wilding, who works for event sponsor Contact Energy, completed the 125km race in 5hr 42sec.
He won the New Zealand marathon mountain bike title at the Karapoti Classic, in Upper Hutt, last month.
"I've been trying to get down here to this race for a while. I heard it was a good thing. It was really hard . . . I will try and come back to break the five hours."
Only three riders have broken 5hr in the arduous race across two remote South Island high country stations.
That was in its first year, 2008, on a course that was later found to be short by several kilometres.
Marcus Roy, of Southland, holds the race record set that year of 4hr 44min 8sec.
Wilding's time is the fastest on the correctly measured course.
Meanwhile, Dunedin's Kath Kelly achieved a hat trick, winning the open women's race in 5hr 44min, 2min faster than her time last year and 18min slower than her 2008 record.
"It was really tough out there.
I got frozen," a triumphant Kelly said as she collected her prize.
Fastest overall in the 95km event were Wayne Miller (Gore), racing in the veteran men's category, in 4hr 52min, and Lucy Fullerton, of Wanaka, who won the open women's race in 5hr 50min.
Jeremy Murray-Orr, of Wanaka, won the 95km open men's race in 5hr 19min.
The conditions on Saturday were challenging, with rain setting in about an hour into the event.
The mud and wind caused technical, physical and mental problems for the soaked and messy 585 competitors in the 95km and 125km events.
Safety co-ordinator Aaron Nicholson said four male cyclists received medical centre or hospital treatment: one broke his leg in a fall near Hunter Valley Station homestead; another received severe bruising to his upper leg and groin area after colliding with his handlebars at the top end of the Hunter Valley; the third broke his collarbone in a crash about 10km into the 125km event on State Highway 6 near Lake Hawea; and the fourth needed about 30 stitches to his arm after falling from his bike, also on State Highway 6.
None of the patients required evacuation by helicopter, which was on stand-by.
Ambulances or private vehicles were used to transport patients to the Wanaka Medical Centre and Dunedin Hospital.
Three cyclists - two Australians and a New Zealander - were retrieved by a four-wheel-drive vehicle after acknowledging at the half-way point they could not continue.
Nicholson said the trio were experienced road cyclists on their first mountain bike challenge "and in a world of hurt".
Next year's race will be held on April 16 to avoid a clash with Anzac Day and Easter weekend, which both occur at the same time.
The race will return to Anzac weekend in 2012.
