Potchefstroom - James Franklin battered a late half-century to lift New Zealand to 260-9 in the third one-day international, raising hopes of inflicting an historic first home series whitewash on South Africa.
Franklin was 53 not out off 52 balls with three fours and a six after Lonwabo Tsotsobe and Ryan McLaren shared eight wickets.
Tsotsobe struck twice early in his 4-45, but New Zealand recovered with successive half-century partnerships between Grant Elliott and Colin Munro and Munro and Franklin. Munro's maiden half-century, a 57, and Elliott's 54 helped to hold together New Zealand's innings after the Black Caps were 68-4 and 129-5.
New Zealand leads the series 2-0 and can become the first team to sweep a one-day series in South Africa.
New Zealand 260-9 in 50 overs (Colin Munro 57, Grant Elliott 54, James Franklin 53 not out; Lonwabo Tsotsobe 4-45, Ryan McLaren 4-52)