Blackcaps vs Bangladesh: Kane Williamson century sees NZ lead build on day three

New Zealand have recorded their biggest-ever test score, with skipper Kane Williamson recording his second double-century against Bangladesh in Hamilton.

With the final ball before afternoon drinks, Williamson swung the ball to the boundary for four to bring up his 200 and promptly declared the innings over at 715/6 - a lead of 481 runs.  

New Zealand's previous best test score was 690 runs against Pakistan in 2014.

Williamson notched up his 20th test century, as his team built on their commanding lead through the morning on day three of the first test.

He was unbeaten on 166, as the teams went to lunch at 605/6, and reached his double-century off 257 balls.

The 28-year-old also passed the 6000-run milestone in just his 120th inning, putting him on pace with the likes of West Indian great Brian Lara and Australia's Matthew Hayden.

Williamson's ton also rounded out a trio of centuries for the top of the NZ order for the first time, after triple-figure efforts from openers Jeet Raval and Tom Latham on day two.

Nightwatchman Neil Wagner was the first wicket to fall on Saturday morning, the five-wicket hero adding to his heroics with the ball, by slashing his way to a new high score of 47 from just 35 balls, before being caught behind.

With the penultimate ball of the morning, BJ Watling was dismissed by a sharp catch from wicketkeeper Liton Das, off the bowling of Miraz for 31.

All-rounder Colin de Grandhomme joined Williamson at the wicket and threatened to reach his century before his captain's double, smashing 76 runs off just 53 balls, including five sixes, before the declaration.

By stumps on the third day, Bangladesh were 174/4, still 307 runs away from making New Zealand bat again.

First-inning centurion Tamim Iqbal led his team's fightback with 74 runs, but was eventually caught behind by wicketkeeper BJ Watling, off Tim Southee's bowling.