Williamson celebrates his second Test double hundred Getty

It was a historic, record-shattering day for New Zealand at the Seddon Park, which witnessed them soar to their highest ever Test score - 715 for 6. Their batting coach Craig McMillan, who was also in charge when New Zealand piled up 690 in Sharjah in 2015 - their then highest Test score, was delighted with the feat and with where the hosts find themselves in the Test match.

"It was right up there [with the best]," McMillan said after the third day's play in Hamilton. "Obviously, it was historic in the amount of runs scored, and the contributions throughout the innings makes it very special, and one that the guys are really proud of."

Kane Williamson was at the center of the effort, scoring an unbeaten double hundred to launch an all-out attack on Bangladesh on the third day. He built on a record 254-run opening partnership between Jeet Raval and Tom Latham, both of whom hit centuries, to go on and compile his second double ton.

"He was sublime today," McMillan said of Williamson. "Whenever the Bangladeshi bowlers missed, he hurt them, he was very efficient when they offered scoring opportunities and created those partnerships that we talk a lot about.

"It's not easy, and it takes a lot of hard work behind the scenes that allows him to play like that. He's very hard to bowl at as he bats 360 degrees - all around the wicket. Bowlers only have to err a fraction with Kane, and he hurts them, and we saw that today. A terrific knock all around."

Even though Bangladesh got off to a good start on a very flat pitch, the New Zealand bowlers picked up four crucial wickets, ensuring that New Zealand still lead by a hefty 307 runs going into the fourth day.

Williamson's current highest score is 242 but he declared well short of it, asking Bangladesh to bat right after he got to his double hundred.

"The milestones weren't an issue at all. We wanted to bat for a period where we could see the wear and tear in the surface - starting to see those cracks open up and develop a little bit. [Williamson] obviously reached that milestone and thought 'now's the time'.

"And we wanted the bowlers to have a decent crack, not just a short hour at the end of the day. To pick up those four wickets was very satisfying at the end of the day."