By stumps the West Indies had negotiated some probing bowling to finish on 49 without loss after 26 overs.
All four bowlers had their moments but Kraigg Brathwaite (20) and, more surprisingly, John Campbell (22), presented a solid case for a draw. Neither played a shot to inspire poets, although Campbell boldly took on the hook off Tim Southee, easily clearing the fine leg fence.
Kyle Jamieson created the only moment when an umpire was asked a serious question. Wayne Knights, in his first test, correctly declined the opportunity to raise his finger.
Southee and Trent Boult both swung the ball early, sometimes past the bat, but they would have been disappointed that the Kookaburra didn't misbehave a bit longer.
Neil Wagner was the most threatening. He charged in with typical enthusiasm but was atypically fuller in length until late in the day when he reverted to around-the-wicket. Immediately the tone of the contest changed, with a leg slip, short leg, two men back on the hook and a fly slip.
Campbell, comfortable until then, suddenly found himself fending the ball off his chest. We could be seeing a lot of that for the rest of the test unless the characteristics of the pitch change dramatically.
This is not a wicket that is easy to score freely on, especially early in your innings, but neither is it one where you can expect to roll through the line-up, though it might have looked that way when the covers were removed yesterday.
The surface is not abrasive enough to bring reverse swing into play, there is no specialist spinner (and little turn) so New Zealand's five-strong seam attack will need to work hard and rely on the odd error of batting judgement to find the requisite 20 wickets.
One man who didn't make too many errors was Williamson. He was better on day two, as you'd expect as the green grass burned off to brown.
A back foot punch through point took him to three figures – the 22nd time he has reached that milestone – and he carried on in serene fashion thereafter.
Batting was a different art at the other end. Ross Taylor nicked off early for 38 and Henry Nicholls added another failure to a string of low scores.
In a vacuum, Nicholls' expansive drive – caught on the second attempt in the slips by Jason Holder – looked wildly undisciplined compared to monastic denial showed by Tom Latham and Williamson, but that's unfair.
The southpaw had dug in for the 32 balls preceding that and probably felt he had earned the right to try to access the cover boundary. It was a technical, rather than mental, error.
Tom Blundell provided staunch support during a 72-run stand but 14 off 63 balls tells a story. Shannon Gabriel, who has developed a big heart to match his physique, ripped a quick one through his defences to trap him in front. Donald Trump had more chance of overturning the election result than Blundell's review had of succeeding.
Daryl Mitchell looked comfortable enough getting to nine off 37 but nicked out softly, before Williamson found in Jamieson (51 not out) a batsman to make things look almost as easy as him.
What can you say about Williamson that doesn't feel like the repetition of an endless list of virtues?
About the only thing he doesn't get enough credit for is his strike rate, but he can score rapidly as he showed by moving from 151 to 251 in just 106 balls.
That's when he holed out in the deep to Roston Chase off Alzarri Joseph and among the disappointment at not clearing the rope there was probably relief, too.
Williamson otherwise might have been left with a choice of whether to stick in for a triple ton or declare. You know he would have chosen the latter and you know it would have disappointed all those watching.
You can't please everybody, even if Williamson gets closer than most.