Pakistan Saturday registered their second win in the ongoing tri-nation series in New Zealand as skipper Babar Azam powered his side by scoring 79 runs off 58 deliveries.
After choosing to bat first, the Black Caps appeared to be on course for a modest 147-run total at Hagley Oval before Chapman's 32 off 16 balls, which featured three fours and two sixes.
Pakistan went clear in the series as they chased down the target, having beaten Bangladesh by 21 runs in the series-opener at the same venue on Friday.
The three teams are using the week-long tournament to prepare for the T20 World Cup in Australia this month.