Duffy claimed 1-30 from his four overs to finish the series with eight wickets, while New Zealand’s other four front-line bowlers each returned economy rates exceeding 11.
After Matt Henry and Mitchell Santner claimed early wickets to remove Sri Lanka’s openers, Perera took charge through a blistering partnership with skipper Charith Asalanka (46 off 24).
The pair put on 100 from 45 balls as the Black Caps’ bowlers struggled for answers through the middle overs, and only economical death overs from Mitchell and Duffy saved the batters from chasing an even bigger target.
That chase began in promising fashion as Ravindra and Tim Robinson (37 off 21) put together an 81-run opening stand in 7.2 overs. Ravindra looked like the key man but, after setting a new high T20 international score, was bowled by Asalanka in the 13th over.
The required rate quickly climbed before Mitchell threatened to change the match in the 15th, hitting Asalanka for four straight sixes as his side’s win probability jumped by almost 60%.
But Mitchell’s dismissal by Nuwan Thushara left too much work for the tailenders, with a couple of big hits from Zak Foulkes (21no off 13) not quite enough.
The two teams will now meet in a three-match ODI series starting at the Basin Reserve on Sunday.
The Alternative Commentary Collective is covering every home Black Caps test this summer. Listen to live commentary here.
Kris Shannon has been a sports journalist since 2011 and covers a variety of codes for the Herald. Reporting on Grant Elliott’s six at Eden Park in 2015 was a career highlight.