Mike Hesson called for New Zealand to raise their game with the bat after they suffered a 16-run defeat to Pakistan in the first Twenty20 international on Friday.
The Black Caps came into the opening game of the three-match series on the back of a 2-0 victory over Sri Lanka, but they were brought back down to earth at Eden Park.
Mohammad Hafeez top scored with 61 as the tourists posted 171-8 after being put in to bat by Kane Williamson, with Adam Milne claiming career-best T20 international figures of 4-37.
Williamson made 70 in reply, his highest T20 international score, and Colin Munro followed up his sensational knock against Sri Lanka on Sunday by smashing 56 from only 27 balls, but New Zealand were all out for 155.
And Black Caps coach Hesson expects an improvement from his batsmen in the remainder of the series.
"The way Colin played he certainly got us to a point where we were in a position to win," said Hesson.
"Once he got out there was some poor decisions made under pressure and that is something we will need to rectify."
He added: "You lose a game that is relatively close, you reflect on lost opportunities. With the bat we need to be more clinical with our decision making."
Henson was full of praise for Pakistan captain Shahid Afridi, who was named man of the match after taking 2-26, holding three catches and scoring 23 from only eight balls.
"He's an explosive player," said Hesson. "We have a come across him a few times in T20 and have a number of plans for him but if you don't execute then he is able to take you apart with the bat.
"That cameo gave them some impetus. With the ball, we were able to take to him early but he came back really well. He is a fine cricketer and he has been around a while so he is a pretty wily campaigner."
Pakistan paceman Mohammad Amir took 1-31 off four overs and also had two catches dropped off his bowling on his return after serving a five-match ban for his part in a spot-fixing scandal.
The two sides head to Hamilton for the second game of the series on Sunday.