Sanford, a two-time Olympian, was second-fastest after his first heat and maintained that place with two solid runs.
He was third on the same track last year.
"It was a relief to put down two good runs and I am very happy to have finished in second," Sandford said yesterday.
Eustace, a Wanaka physiotherapist, was fifth in a snow-affected race that meant the second heat was cancelled.
"I was just warming up and getting prepared for the second heat but the snow was getting heavier.
"When they announced that the first heat of the race would be the final race result, it took me a while to realise that I had placed fifth but it is a great result, although still room for improvement," she said.
The men's race was won by World Cup leader Martins Durkurs, of Latvia. American Matt Antoine was third.
The women's race was won by Lizzie Yarnold, of Great Britain, Shelley Rudman, of Great Britain, was second and Katharina Heinz was third.
Both Sandford and Eustace said they felt "great" to be on the podium ahead of other athletes who have more support staff and financial assistance.
"We are a small nation with limited coaching and no home track. It feels that we punch well above our weight. It is a good day for New Zealand skeleton and winter sport," they said.
The best New Zealand skeleton result comes from Bruce Sandford, who was the 1992 world champion.
With next year's world championships to be held at the St Moritz track, Sandford and Eustace are hoping to improve on this year's results and win a top-three place in 2013.
