AUCKLAND: Martin Guptill hit the fastest half-century by a New Zealand batsman, only for Colin Munro to better it moments later as the hosts needed just 10 overs to rout Sri Lanka by nine wickets in their Twenty20 match on Sunday, winning both matches of the series.
Grant Elliott took 4-22 as New Zealand restricted Sri Lanka to 142-8 batting first.
Guptill then reached his 50 off 19 balls and Munro needed just 14 deliveries, hitting a six on the last ball of the tenth over to end the lopsided contest, with New Zealand finishing on 147-1.
Munro's half century, which included seven sixes, was the second-fastest in all T20 internationals, behind only a 12-ball 50 by India's Yuvraj Singh.
New Zealand had previously won the two-match test series against Sri Lanka 2-0 and the five-match one-day series 3-1 with one match abandoned.
In losing this series, Sri Lanka likely surrendered its top-ranking in Twenty20 cricket to the West Indies ahead of the World Cup in India in March.
Munro missed both the test and one-day series but returned as a Twenty20 specialist and his barnstorming innings should be enough to seal his place at No. 3 in the New Zealand order for the World Cup.
He had a hard act to follow when he came to the wicket with Guptill just out for 63 after an 89-run opening partnership with Kane Williamson. Guptill had already taken the long-handle to the Sri Lanka bowlers, hitting six fours and five sixes.
"Guppy's had a very good record this summer and to beat that record was very pleasing for myself," said Munro who was named Man of the Match.
New Zealand captain Williamson had the best seat in the house to watch the power hitting as he shared the swift opening stand with Guptill, then another of 58 with Munro. He finished with a comparatively sedate 32 not out from 21 balls.
Sri Lanka leg-spinner Jeffrey Vandersay conceded 41 runs from two overs and Dushmantha Chameera 46 from three.
"To restrict them to the score we did I thought was a good effort but I still thought it would be a bit of a scrap on that wicket as it was holding up a fraction," Williamson said.
"But it didn't seem to be a problem for those two guys and they cleared the ropes consistently so that's exciting to see for our team and hopefully we can build on this and keep moving on with our T20 cricket."
New Zealand immediately starts a three-match series against Pakistan.
Angelo Mathews held together the Sri Lanka innings with an outstanding unbeaten 81 from 49 balls while his teammates too often threw away their wickets with rash shots.
Tillakaratne Dilshan, who made 28, was the only batsman other than Mathews to bat responsibly.
"I'm really disappointed with the way we played," Sri Lanka captain Dinesh Chandimal said. "Thanks to Angelo we were able to put a competitive total on the board but I'm really disappointed with the way we bowled.
"Martin (Guptill) is in good form and New Zealand played awesome cricket."