New Zealand 143 for 3 (Guptill 71, Conway 36, Phillips 34*, Meredith 2-39) beat Australia 142 for 8 (Wade 44, Finch 36, Sodhi 3-24, Boult 2-26) by 7 wickets
A dreadful finish to Australia's innings opened the way for New Zealand to rumble to a seven-wicket victory and a 3-2 T20I series triumph, as Martin Guptill and Devon Conway finished the bout the way they had started it in Christchurch.
A pair of wins in spectator-free games had allowed Australia to turn up for the final game with a chance to win from 0-2 down, but on a sunny Sunday afternoon with a crowd again present, Kane Williamson's side scotched early momentum enjoyed by the visitors when Matthew Wade and Aaron Finch were in harness to completely dominate the closing overs and leave a target of just 143 to win. Ish Sodhi, Mitchell Santner and Trent Boult all made valuable contributions.
Guptill and Conway, joining forces as openers, then powered to a stand worth 101 to mean that a rapid second spell from Riley Meredith was nowhere near enough to prevent the match and series going comfortably New Zealand's way. Having been eliminated from the World Test Championship final by India's victory over England the night before, it has not been a happy 24 hours for the Australians.
Wade roused by his demotion
On a surface that promised to be tired by its third consecutive use for a T20I, Finch was very happy to bat first, but with one significant change: switching Josh Philippe up to open and demoting Wade to No. 3 after four underwhelming games. The move did not work out for Philippe, who took a huge swing at his first ball from Boult and was extremely lbw as it swung back just enough down the line of the stumps, but it had the effect of rousing Wade into action.
Finding the boundary on either side of the wicket, and taking his runs with equal alacrity off pace and spin, Wade allowed Finch to bat comfortably in his slipstream, and at 74 for 1 in the 10th over a tally of at least 160 beckoned. Even after Finch fell, cutting Sodhi, and Glenn Maxwell picked out deep backward square leg second ball, Australia were well placed at 99 for 3 with seven overs remaining - or so it seemed.
Australians swing themselves off their feet
In addition to Philippe, the tourists also elected to promote Ashton Agar to join Wade, but the shuffling did not aid their efforts to build a second set of momentum in the closing overs. Wade found himself starved of the strike once wickets began to fall, and while still seeing the ball well, ended up miscuing a Boult knuckle-ball from the bottom of the bat to find deep midwicket. Marcus Stoinis and Agar threatened briefly, but upon being presented with consecutive friendly full tosses from Sodhi, both found fielders.
Mitchell Marsh averted a full tosses hat-trick, and clumped one big blow beyond wide of long-on, but when he was comprehensively yorked by Tim Southee after an ordinary start to the final over, the innings had slipped well away from Australia in terms even of putting up a total beyond 150. The tally for the final seven overs of the innings was to read 43 runs at a cost of five wickets, a strong endorsement of the way Williamson marshalled his bowlers and fielders to frustrate Australia after such a promising start.
Guptill, Conway take control
The day's second change in opening partnerships had Conway promoted to start New Zealand's chase alongside Guptill. This time, the fresh union was to prove decisive to the match and the series, as they were not parted until New Zealand had 100 on the board and a small Wellington crowd dancing in the aisles. There was some useful assistance for spin, and Meredith's speed was again considerable, but Guptill and Conway got themselves set before launching with telling effect.
Thirteen came from the third over, 11 from the fifth, 12 from the sixth and then a monumental 23 from the ninth twirled down by Adam Zampa, including a Guptill six that landed on the "cake tin" lid, aka the roof of the stands. A partnership ultimately worth 101 before Conway's exit provided a more than useful extra option for New Zealand in terms of their thinking for the T20 World Cup later this year: Conway, though, seems adept at most batting tasks.
Meredith's speed can't turn the game
Finch brought back Meredith for a final tilt at the rush of wickets needed to turn the game, and the swift Tasmanian was at least able to have plenty of watchers take notice by grabbing two in as many balls. Conway's slice to deep point was only partly to do with the bowler, but the fast off cutter that pinned Williamson in front of leg stump - meaning Meredith had dismissed the New Zealand captain twice in three balls this series - will be remembered by the Australia selectors.
Glenn Phillips' first few balls from Meredith were also uncomfortable for their sheer pace, but once New Zealand's No. 4 got used to the velocity, he was able to respond with shots that meant the fast bowler's analysis was a seemingly unexceptional 2 for 39. That left the stage clear for the finish, as Phillips delivered the series to his side after Guptill fell, swatting Zampa for two sixes in three balls to win with 28 balls to spare.
Daniel Brettig is an assistant editor at ESPNcricinfo. @danbrettig