New Zealand 143 for 4 (Williamson 73*, de Grandhomme 41*) beat Bangladesh 141 for 8 (Mahmudullah 52, Ferguson 3-32)
Scorecard and ball-by-ball details

Kane Williamson timed his unbeaten 73 beautifully to help New Zealand to a six-wicket win over Bangladesh in the first T20 in Napier. Along with Colin de Grandhomme, he rode out a early wobble as Bangladesh took three wickets in seven overs while defending 141.

Williamson struck five fours and two sixes in his 55-ball knock, surviving two chances on the boundary that were down to errors in judgment by Soumya Sarkar and Imrul Kayes who stood too far inside the rope at deep midwicket and long-off respectively.

Until 10.1 overs, Bangladesh were threatening New Zealand with a heist. Shakib Al Hasan had taken a stunning catch running from deep square leg to midwicket in the third over to get rid of Neil Broom. Mustafizur Rahman removed Colin Munro for a duck in the next over and Shakib had Corey Anderson caught at long-off. When Sarkar and Mashrafe Mortaza combined to run the debutant Tom Bruce out at the start of the 11th over, the visitors might have felt on top.

But de Grandhomme slammed a big six over midwicket in the same Mashrafe over before Williamson struck Shakib for a four - the result of Sarkar standing too far inside - and six. He reached his sixth fifty in T20Is before de Grandhomme thumped two more sixes, the last one over cover to seal the game with 12 balls to spare. The pair added 81 runs for the fifth wicket with de Grandhomme unbeaten on 41 off 22 balls.

Earlier Mashrafe believed he was giving his batsmen the best use of the flat McLean Park pitch but apart from Mahmudullah, who reached his third T20 fifty, the rest responded poorly.

Kayes edged Matt Henry in the second over and things didn't get much better after that as Bangladesh lost three wickets in five balls towards the end of the Powerplay.

Tamim Iqbal was the first to go, giving debutants Ben Wheeler and Tom Bruce their first wicket and catch respectively. Then Lockie Ferguson became only the second bowler ever to take wickets off his first two balls in T20Is. Sabbir Rahman popped a full toss to mid-on rather tamely but Sarkar was undone by a sharp outswinger that took the edge to gully. The hat-trick ball was a yorker but Mahmudullah jammed down bat just in time.

After the worst ODI series of his career with scores of 0 1 and 3, Mahmudullah bounced back with 52 off 47 balls that included three fours and three sixes over midwicket, long-on and long-off. He added 37 and 32 for the fifth and sixth wicket partnerships with Shakib Al Hasan and Mosaddek Hossain, who struck two sixes in his 17-ball 20. New Zealand had to wait until the final over to get rid of Mahmudullah. Ferguson was the successful bowler again, finishing with 3 for 32.

Left-arm quick Wheeler also made an impressive debut with his two wickets while de Grandhomme, Santner and Henry picked up one each.

Mohammad Isam is ESPNcricinfo's Bangladesh correspondent. @isam84