The Black Caps have beaten South Africa by 32 runs in the second and final T20 overnight.
New Zealand reached 7-177 after their 20 overs, with opening batsman Martin Guptil top scoring with 60 off 35 balls.
Williamson (25), Elliot (20) Neesham (28) and Munro (18) all made valuable contributions.
South Africa lost two wickets in the first three overs of their run chase, to make things difficult for the middle order.
Farhaan Behardien top scored for the hosts with 36, while Rossouw and Miller were the only other batsmen to score over 20, as the Proteas fell 32 runs short, reaching 8-145.
The two sides will now play a three match ODI series starting on Wednesday.
See the scorecard at Cricket.com.au
