They were the first to reach the summit of Nevado Cayesh, the 5721m high needle-like mountain in the Peruvian Andes that had already beaten teams from Switzerland and the United States.
Dunedin-born Mr Davis, then an engineer working in Bluff, broke a rib in an avalanche more than two weeks earlier but still managed to help cut a route towards the summit.
Pride grew as the men inched closer to the top.
"We passed those binoculars around the five of us at the camp, watching in the beautifully clear air as they slowly made their way up," Mr Davis (81) said yesterday.
"Of course, they were a long way above us, but we were still urging them on. It seemed to take forever for them to move what looked like a short distance to the top. But this was hard going, a real challenge unlike anything we'd experienced before."
It was July 21, 1960 when Lindsay Stewart, Dal Ryan, and Lynne Crawford, of the New Zealand Andes Expedition, scaled the steepest mountain in the Cordillera Blanca.
The team chipped away at the mountain for nearly a month, establishing three camps and cutting a route through ice, snow and stark overhangs before the push to the top.
There were plenty of challenges in the days before the final climb.
Mr Crawford suffered congestive heart failure - he recovered when he was given oxygen from a welder's gas bottle - Dr Stewart contracted an infection, and Dick Wood had hurt his back in a fall.
Lloyd Warburton and Mr Davis were hurt when they were hit by an avalanche as they cut steps above camp 1, the second camp on the climb.
"Even coming down, there were challenges for the men.
The light was going on the descent, and fatigue and visibility meant they had to shelter the night in an ice cave.
When we saw the torches coming down the valley, we knew we could celebrate."
Their achievement was lauded in New Zealand newspapers, but it might never have happened.
The team originally planned to mount an expedition to the Antarctic, but its seats on an American transporter were taken by the New Zealand Government.
It would have taken too long to get permits for a last-minute trip to the Himalayas "so the next decent climb, as we could see it, was in the Andes", he said.
The team climbed Mt Talbot, near the Homer Tunnel, in Easter 1960 before making its way to South America in May.
They also attempted the unclimbed east ridge of Nevado Huascaran, the highest peak in Peru.
Federated Mountain Clubs of New Zealand executive member Robin McNeill, of Invercargill, said the Nevado Cayesh climb was the most significant since Sir Edmund Hillary climbed Everest in 1953.
Mr Davis, now a Dunedin engineer, said he was the last surviving member of the expedition.
He would be proud to mark the achievements of such wonderful climbers next month.
