Seven Bangladesh wickets stood between a Kiwi victory ahead of the final day at Wellington but it took the hosts just the one extended session to wrap up a crushing win.
Wagner picked up five wickets in a terrific 10-over spell on day five to bundle out Bangladesh for 209 in their second innings.
Resuming the day at 80-3 and still trailing by 141 runs in the second innings, Bangladesh lost Saumya Sarkar early to Trent Boult on day five.
Mohammad Mithun was looking determined at the other end and was starting to form a promising stand with Mahmudullah before Wagner produced an inspired spell of hostile short-pitched bowling.
The left-arm pacer had Mithun (47) caught at backward square leg before sending back Liton Das and Taijul Islam in quick succession to reduce the visitors to 170-7.
Mustafizur Rahman offered some resistance with the bat before it was finally broken by a returning Boult. That prompted the umpires to extend the morning session at Wellington and it was just the invitation Wagner needed to clean up the Bangladesh tail.
Skipper Mahmudullah (67) was the sole Bangladesh batsman to register a half-century with the right-hander being the penultimate wicket to fall on the final day.
It was a fine display by Kane Williamson’s men who secured victory despite the first two days of the Test being lost to rain. The innings win means the Kiwis have clinched the three-match series against Bangladesh with an unassailable 2-0 lead.
The third and final Test between the two sides will get under way at Christchurch on March 16.
Bangladesh: 211 and 209
Mahmudullah: 67 (69)
Neil Wagner: 5-45
Trent Boult: 4-52
New Zealand: 432-6 declared
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