New Zealand demolished Sri Lanka with a nine-wicket victory in the second Twenty20 international to level the series Wednesday, as opener Tim Seifert finished on 79 not out.

Black Caps bowler Adam Milne had earlier taken five wickets for just 26 runs as Sri Lanka were skittled for just 141 runs.

Seifert then helped steer New Zealand to victory as the hosts hit a rapid-fire 146-1 in reply after 14.4 overs.

Their win in Dunedin meant New Zealand levelled the series 1-1 ahead of the decider this Saturday in Queenstown.

Sri Lanka had won the opening T20 match last Sunday in Auckland.

Milne's impressive bowling display meant New Zealand were set a target of 142 to win.

Opener Chad Bowes was caught after hitting 31 off 15 balls before Seifert peppered the boundary in a partnership of 106 with New Zealand captain Tom Latham, who finished 20 not out.

Seifert then wrapped up New Zealand's innings in style with two towering sixes.

It was a brutal defeat for Sri Lanka, who had made a good start.

Kusal Perera (35) and Dhananjaya de Silva (37) put on a middle-order partnership of 62 off 46 balls to steer the visitors to 99-4 after 12 overs.

The tourists then collapsed by losing their next six wickets for just 42 runs as New Zealand's seamers found their length to devastating effect.

Charith Asalanka was the last Sri Lankan batter to offer any resistance, chalking up 24 runs off 19 balls.

Milne did the most damage for New Zealand, picking off Sri Lanka's tailenders Dilshan Madushanka and Pramod Madushan without a run being scored.

Sri Lanka have lost both the Test and one-day international series 2-0 during their tour of New Zealand.