Striking half-centuries from to top up with Daryl Mitchel blasting a 27-ball 61 runs, Williamson’s 57 and later a raging attack from Tim Southee, New Zealand threw Pakistan to chase a massive 227 runs to win in their first T20 off five match series.
Tim Southee became the first player to 150 wickets in Twenty20 internationals as New Zealand beat Pakistan by 46 runs in their series opener in Auckland on Friday.
Veteran seam bowler Southee claimed four wickets to pass the milestone and help dismiss the tourists for 180 in the 18th over in response to New Zealand's imposing 226-8, handing them first blood in the five-match series.
Southee's figures of 4-25 were the best of a run-dominated encounter at Eden Park and took him to 151 wickets in T20 internationals, 11 more than Bangladesh spinner Shakib Al Hasan.
He finished the job as Pakistan's run chase capitulated after Babar Azam was the seventh wicket to fall in the 17th over, with the former captain having accelerated to 57 off 35 balls to keep his side in contention.
There were starts for openers Saim Ayub (27) and Mohammad Rizwan (25) but Azam struggled to find support from his teammates before being caught at cover by Kane Williamson off Ben Sears' bowling.
New Zealand's boundary-laden innings was the highest Pakistan had conceded in a T20, surpassing the 221-3 England scored in Karachi in 2022.
Daryl Mitchell blasted 61 off 27 balls and captain Williamson's 57 took 42 balls as New Zealand built on an explosive start from opener Finn Allen (34), who struck 24 runs off the third over, bowled by Pakistan captain Shaheen Shah Afridi.
Pakistan's new-look attack struggled to protect the ground's notoriously short boundaries, conceding 21 fours and 11 sixes.
Seamer Abbas Afridi impressed in his first international appearance in any format with 3-34 off four overs, although fellow-debutant Usama Mir had his leg spin attacked by Mitchell in particular and finished with 0-51.
Shaheen, who took 3-46, led Pakistan for the first time after Babar forfeited the captaincy in the wake of their failure to make last year's 50-over Cricket World Cup semi-finals.
New Zealand spin-bowling allrounder Mitchell Santner wasn't selected after testing positive for Covid-19 earlier in the day.