Guy McKinnon, a professional search and rescue team member at Aoraki-Mt Cook, was said last night to have accomplished "once in a generation" ascents.
His latest feat involved walking for two days in cold and difficult conditions from northwest of Lake Wanaka to the base of the east face of the ice-covered Popes Nose, and scaling its 2700-metre peak on a continuously vertical trajectory in just five hours on Friday.
Although the peak has been climbed three times before, twice in summer and once in winter, McKinnon is its only solo conqueror and all his predecessors were flown to its base by helicopter.
New Zealand Alpine Club general manager Sam Newton said the only other winter climb, 24 years ago by a party of four, took two days.
"It's an incredible climb - an incredible feat of talent and endurance," Mr Newton said.
Not content with that, McKinnon then descended from Popes Nose to the Upper Volta Glacier to the north for an assault on the northeast face of nearby Mt Aspiring.
But that climb was thwarted by poor conditions and the weather was packing in so McKinnon, aged in his late 30s, battled across the Bonar Glacier in gale-force winds and a whiteout to reach the sanctuary of French Ridge Hut - which he had passed on his trek to Popes Nose.
The reclusive climber could not be reached last night, but in an earlier statement said: "The unfolding of this attempt was long and arduous beyond words and required mental effort and determination in excess of anything previously required of me."
McKinnon, who in 2010 became the first person to make solo ascents of all 34 of New Zealand's 3000m-plus mountains, last year succeeded in scaling the west face of 2723m Mt Tutoko - long regarded as one of the country's last great challenges.