Queenstown - Tim Seifert was the match-winner for the second straight game as New Zealand clinched the T20 series against Sri Lanka with a tense four-wicket victory in Queenstown on Saturday.
Seifert blasted a career-high 88 off 48 balls to fire the Black Caps to 183-6 from 19.5 overs after the tourists had posted 182-6 in the third and final game at John Davies Oval.
The opener struck 10 fours and three sixes in an innings that bore many of the hallmarks of his unbeaten 79 when New Zealand levelled the series at Dunedin on Wednesday.
Captain Tom Latham provided the only meaningful support with 31 off 23 and New Zealand's middle order nearly conspired to lose the game after Seifert departed with four overs remaining.
Needing to score at little more than a run-a-ball at that stage, the Black Caps stuttered.
Needing 10 runs to win off the final over bowled by Lahiru Kumara (3-38), Mark Chapman struck a six off the first ball before he was the first of three New Zealand wickets to fall.
With two still needed off the last two deliveries, Rachin Ravindra held his nerve to find a gap in the outfield and secure the 2-1 series win.
Latham conceded the run chase should not have become so tight at the death.
"They put us under pressure so it was good to see the way the guys responded to that," Latham said.
"The way Timmy Seifert went out there and played was really important but obviously it wasn't ideal going down to the last couple of balls.
"I'd say we always had it under control though."
It completes a disappointing tour for Sri Lanka, who lost the Test and ODI series by the same 2-0 scoreline but were more competitive in the shortest format.
Captain Dasun Shanaka said his team adjusted gradually to New Zealand conditions and suggested Sri Lankan cricket officials should take careful note.
"I think it's about preparation. We should make sure when we come here again, we should come at least two weeks, three weeks before we play," Shanaka said.
"Once we got into the T20 series we started looking a different team."
Sri Lanka gave themselves a shot at victory after Kusal Mendis struck a rapid 73 off 48 balls, taking full advantage after being dropped by Daryl Mitchell at slip when on 10.
The opener-wicketkeeper went on to hit six fours and five sixes in his 12th half-century, falling just short of his career-high score of 79.
Having been asked to bat, Mendis was the dominant figure in an opening stand of 76 with Pathum Nissanka (25 off 25), before putting on a further 46 with Kusal Perera (33 off 21).
Wickets fell rapidly over the closing overs, preventing the tourists from going close to 200.
Seifert has not been included in New Zealand's squad for the white ball tour of Pakistan beginning on Friday as he is expecting the arrival of his first child.
Sri Lanka's next assignment is a two-Test home series against Ireland, beginning on April 16.