His innings, as pleasing as it must have been personally, would have especially satisfied Williamson given how important it was against an Irish side hoping to add another big scalp, having already upset England.
On a day when each of the top five made starts, the captain was the lone batsman to capitalise, cracking a half century that formed the basis of the Black Caps’ formidable total.
After being sent in, New Zealand’s openers scratched to 16-0 after three overs, with Devon Conway being dropped. Finn Allen (32 off 18) sparked to life in the fourth, hooking the first six over fine leg, but then fell while driving sharply.
That brought Williamson to the middle as New Zealand reached 52-1 at the end of the powerplay, with both batsmen battling for fluency early in their partnership.
Williamson had preached patience yesterday and at first practised that virtue, with the pair collecting only one mis-timed boundary in their first 26 balls together.
But the drinks break arrived at the right time - with the Black Caps on 75-1 at the halfway mark - and Williamson looked a different player from that point.
Like against England, the captain had reached 15 runs from 15 balls. Unlike the England game, however, that was when his strike rate skyrocketed.
Williamson started coming down the pitch and combined his unmatched ability to find gaps with a willingness to play expansively, pulling over deep square leg for six in the 11th over.
He and Conway (28 off 33) scored 18 much-needed runs from that over but the opener soon finished a frustrating innings by holing out to long on.
That, though, appeared a decent wicket to lose given it brought to the crease the team’s most in-form batsman. And Glenn Phillips took two deliveries to put one in the stands, slog sweeping over deep midwicket.
But with a brief to attack, Phillips’ (17 off 9) stay was brief, finding deep cover to leave New Zealand on 128-3 after 15 overs.
That was when Williamson really took charge, showcasing a full array of shots as he and Daryl Mitchell (31 off 21) added a dozen from both the 16th and 17th over. Then, in the 18th, Williamson smashed 16 runs in three balls, bringing up 50 with a beautiful slog sweep for six.
His dismissal was the first in Little’s hat-trick as Jimmy Neesham and Santner were both rapped on the pad from their sole delivery, helping Ireland fight back at the death.
It was still an imposing chase but the Irish initially did well to blunt the impact of the seamers before looking to attack the spinners.
That strategy reaped three sixes from the first overs of Santner and Sodhi and, with the required run rate dropping below 10, New Zealand needed a wicket.
Both spinners soon answered that call. Santner was first, showing courage by floating a slower, wider delivery to Andy Balbirnie (30 off 25) and getting him to drag on; then Sodhi followed that lead by dropping his pace to bowl out Paul Stirling (37 off 27).
Ireland reached 72-3 halfway through the innings but had new men at the crease and saw the required rate steadily climb as Santner (2-26) bowled his allotment in succession.
His powers of deception were on full display while inducing a thick outside edge from Harry Tector for his second wicket, while Sodhi (2-31) again matched his teammate.
Lockie Ferguson (3-22) thrived while facing the middle order and, with Tim Southee also picking up a couple of wickets, Ireland were restricted to 150-9, leaving the Black Caps to prepare for a semifinal.
