The Black Caps deserve a box of chocolates or something nice for smashing more than 400 runs in a day.
But the home side surrendered a more commanding position with the loss of six wickets during the final session of day one of its test against Sri Lanka at the University Oval yesterday.
New Zealand opener Martin Guptill returned to form with 156 to help his side post 409 for eight, his third test hundred.
Kane Williamson added a classy 88, while Brendon McCullum thrashed 75 from 57 deliveries.
By and large, Sri Lanka bowled poorly but a good batting performance from its inexperienced line-up today could help the touring side claw back even more momentum.
Sri Lanka got the opportunity to make first use of the pitch but quickly set about squandering that advantage.
Neither Suranga Lakmal nor Nuwan Pradeep could find their way past the middle of the bat often enough and captain Angelo Mathews had had enough after just seven overs.
The medium-pace trundler brought himself into the attack and did a good job of holding up an end.
But at his pace (120kmh), it felt like a waste of the new ball.
Mathews perhaps would have been better served introducing Dushmantha Chameera, who had good energy and some zip.
No-one really looked like getting out until Tom Latham suddenly did.
He had just dispatched a delightful on drive for a boundary but was then caught and bowled the next ball.
Lakmal finally had some success but it was to be the only breakthrough for the morning with the home team going to lunch at 114 for one.
New Zealand continued to pile on the runs after the break.
Guptill had a reprieve, though.
He survived two lbw shouts from Chameera on 78.
The second would have been out had Sri Lanka opted for a review.
Meanwhile, Williamson was seemingly marching towards hundred himself.
He looked in control from the moment he reached the crease.
The way he plays the ball so late and finds the gaps so consistently remains a marvel no matter how many times you see him bat.
He is the master of the late cut and you simply cannot give him any width at all.
But even the best make mistakes and, 12 short of a 13th test hundred, he played a loose drive and nicked out.
Dimuth Karunaratne hauled in a good catch and Pradeep got the congratulations.
With New Zealand 229 for two, there was not too much to celebrate, though.
And the pair had added 173 - a New Zealand record second-wicket partnership against Sri Lanka - in just 233 balls.
Ross Taylor's hasty departure was not followed by any period of consolidation.
Brendon McCullum came out and played as he does.
He flashed and flashed hard. Sometimes he was overly ambitious but who cares?
It is a joy to watch him playing the game the way he wants to play it.
Pradeep got crashed for three consecutive fours.
Chameera got clobbered as well as McCullum brought up 50 in 39 balls.
He was no mood to pull out the block shot and had one look at left-arm spinner Milinda Siriwardana before having a heave.
His first effort made the rope but the second was caught at deep backward square leg by Kithuruwan Vithanage.
But having dominated for so long, the home side faded.
First, Mitchell Santner got an edge.
BJ Watling was caught out by the extra bounce the new ball provided and steered a catch to gully.
Guptill's long vigil came to an end when he feathered a touch through to keeper Dinesh Chandimal and Tim Southee lasted just two deliveries.
Doug Bracewell (32 not out) and Neil Wagner will resume today with the goal of getting their side as close to 500 as possible.
Suranga Lakmal was the pick of the Sri Lankan bowlers with two for 69 from 16 overs.
Snapshots
TOP PERFORMANCE
New Zealand opener Martin Guptill had a reprieve on 78 but otherwise played with renewed confidence in getting through to his third test hundred.
BEST SHOT
Each late cut Kane Williamson plays just gets that little bit better than the previous.
BEST MOMENT
Guptill's 100 of course. It brought New Zealand coach Mike Hesson to his feet.
SRI LANKA'S HIGHLIGHT
The touring side took six wickets in the final session to peg back the home team.
WHAT WILL HAPPEN TODAY?
The Black Caps will be hoping to reach 500 before unleashing Trent Boult and Tim Southee on Sri Lanka's inexperienced batting line-up.
