Martin Guptill’s sixth Twenty20 international half-century for New Zealand led the Black Caps to a series-levelling 32-run victory over South Africa at Centurion on Sunday.

The opener thumped 60 from 35 balls as Kane Williamson's side posted an imposing total of 177-7, which always looked likely to prove beyond their opponents following the early departures of Morne van Wyk (3), Hashim Amla (14) and stand-in skipper AB de Villiers (15).

Despite the efforts of Rilee Rossouw (26), Farhaan Behardien (36) and David Miller (29), South Africa fell some way short on 145-8 as the the Black Caps maintained their three-year unbeaten run in two-match T20 series.

New Zealand, determined to improve on the collapse they suffered in Friday's first game, elected to bat upon winning the toss and made an excellent start as captain Williamson and Guptill took advantage of some sloppy South African bowling.

Williamson (25) brought up the fifty partnership with a magnificent six before he was caught at deep third man by Kyle Abbott off Kagiso Rabada, with Tom Latham departing cheaply soon after.

However, Guptill, dropped by Miller on 37, continued to punish the South African attack with some superb shots as New Zealand moved into three figures.

Guptill's innings finally came to an end in the 12th over, Miller atoning for his earlier error with a fantastic catch low to his right at long-on off Farhaan Behardien.

Miller took another catch to account for Luke Ronchi (6) and give David Wiese (1-26) a wicket, but cameos from Grant Elliott (20), Colin Munro (18) and James Neesham (28) helped New Zealand finish the innings strongly - despite Rabada taking two wickets in as many balls in the 19th over to finish with 3-30.

New Zealand’s bowlers came out firing and were rewarded for their efforts with the third-over dismissal of Van Wyk, caught behind off Mitchell McClenaghan (2-28).

Amla swiftly followed to the pacy Adam Milne (1-27) and De Villiers followed up a slog-swept six off Nathan McCullum (2-31) by skewing his next shot to Neesham at long-on.

When Ish Sodhi (2-27) struck for the first time to remove Rossouw, South Africa were 75-4 after 10 overs.

Behardien and Miller steadied the ship, but the hosts were left with far too much to do and lost wickets in four successive overs on their way to defeat.