Martin Guptill's 48-ball 80 proved to be the decisive innings in New Zealand's 22-run win over Pakistan, that helped them qualify for the semi-final of the World T20 played, in Mohali on Tuesday.

Pakistan came in to the match knowing that their hopes of staying alive in the tournament hinged on a win against New Zealand, but Guptill seized the early initiative, after his captain Kane Williamson won the toss and opted to bat on pitch that favoured stroke-play.

The tall opener, who failed to impress with scores of 39 and 6 from the first two games, belted Mohammad Irfan for a six and a four in the second over of the match. He then thumped Mohammad Amir for three fours in the next over.

The onslaught left a strong Pakistan new-ball attack without answers. Guptill had hit four fours and three sixes in a span of six overs and helped his side race to 50 at over nine runs an over. He scored 32 of his runs straight between long-off and long-on, including two of his 10 fours and all three of his sixes.

Guptill resorted to the sweep shot to counter the spin of Shahid Afridi and Imad Wasim. The strategy helped him dominate even when he misread the delivery off the bowler's hand. Mohammad Sami finally breached Guptill's defences in the 15th over, but the damage had already been done. New Zealand amassed 180 in their innings.

Pakistan have struggled to maintain consistency with the bat through the tournament and that inconsistency was on display once again. Their middle order failed to capitalize on a 65-run opening stand between Sharjeel Khan and Ahmed Shehzad. They managed just 150 for five in their innings.

Guptill collected his seventh Man-of-the-Match award in T20Is, which is the joint-most for New Zealand in T20Is with Brendon McCullum.

"We found early that the wicket was good than what we have been playing on. Wanted to be aggressive and it paid off for us. Got to keep playing the same way, we got enough power in our batting line-up to keep going. The new ball came on a bit more, hopefully we can keep it going," Guptill said.