But Williamson will now cross the Tasman much more hopeful of repeating those feats, having struck 59 runs off 38 balls to lay what could have been a match-winning platform in today's tri-series decider.
Instead, once Williamson fell, New Zealand managed only 29 runs from the final 25 deliveries, stumbling to 163-7.
That total always felt light and, although another superb spell of 2-14 from Michael Bracewell put them on top, the bowlers were unable to mount a successful defence.
The 15th over, bowled by Ish Sodhi, proved particularly costly. Haider Ali and Mohammad Nawaz took 25 runs from the leg spinner, giving him figures of 1-58 and leaving Pakistan needing 42 from the final five overs.
Iftikhar Ahmed eventually sealed victory with a six as Pakistan showed they would be serious contenders to add a World Cup to their tri-nations prize.
But New Zealand will tomorrow hop on a plane also optimistic about their chances of glory ahead of their opener against the hosts on October 22.
That positive feeling, as they so often are for the Black Caps, was sparked by Williamson.
After being sent in, the captain came to the crease to start the second over after Finn Allen blazed three boundaries but fell while seeking a fourth.
Williamson, having scuffled at the crease throughout the year, looked locked in from ball one. That Haris Rauf delivery was driven past point to the fence, while the next was flicked through midwicket for another boundary.
Williamson played one defensive shot then cracked two more fours and, although he was unable to sustain that pace, he also hit two sixes to put his side in a strong position.
His teammates, however, couldn't capitalise once Williamson was dismissed by Shadab Khan, with Glenn Phillips (29 off 22), Mark Chapman (25 off 19) and Jimmy Neesham (17 off 10) managing only cameos.
"It was nice to make a contribution," Williamson told Spark Sport. "Obviously you want a few more and you want to be on the right side of the result.
"[It was] probably a par total. We wanted a few more and to finish off well but we know the Pakistani death bowling has been outstanding.
"The batters coming in and all playing roles throughout the series has been positive, and it's been nice to see signs of improvement."
There will be room for further improvement once Daryl Mitchell returns from injury, though the Black Caps will then face a tough call about whom to omit from their first-choice XI.
Bracewell wasn't expected to be part of that but his series return of 8-84 from 17 overs - when allied to his batting abilities - must make him difficult to drop.
New Zealand, chasing an elusive World Cup, can consider that during few unofficial warm-up matches in Australia next week.
