Angelo Mathews, who retired hurt with hamstring trouble at tea on day four, did not come out to bat, which meant that only three dismissals stood between New Zealand and the series win.
This was a record fourth consecutive series win for New Zealand, with the team having beaten West Indies and England at home in the last summer, and having defeated Pakistan in the UAE earlier this month.
Trent Boult claimed two of those dismissals, bowling Suranga Lakmal with the third ball of the day, before trapping Dushmantha Chameera in front of the stumps with the first ball of his next over. Boult finished with match figures of 9 for 107, having taken 6 for 30 in the first innings.In between those two Boult wickets, Neil Wagner bounced Dilruwan Perera out, having him caught in the square leg region by Kane Williamson, who ran towards the boundary to complete a good overhead catch. Having taken three vital wickets on day four, Wagner finished with wickets of 4 for 48 from his 29 overs in the second innings.
The margin of victory is the greatest for New Zealand in matches not involving an innings result, beating their 254-run win over Zimbabwe in 2016. It is also Sri Lanka's heaviest defeat not involving an innings result, with the 304-run loss against India last year being their previous worst.
Match Coverage
'Matt Henry's catch was the key moment' - Kane Williamson
The substitute plucked a low catch on day four to dismiss Kusal Mendis, breaking a mighty 318-ball stand for the third wicket
Injured Angelo Mathews almost certain to miss Australia tour
The allrounder has been ruled out of the limited-overs leg of the New Zealand tour and faces up to four weeks on the sidelines, according to the physio
'I am going to try and get 1000 every year' - Mendis
Kusal Mendis was a "really happy" man after becoming the youngest batsman since 2005 to score 1000 Test runs in a calendar year
Wagner, Boult bowl New Zealand to record win
New Zealand required only 14 deliveries on the final day to clinch a series win that took them to No. 3 in the Test rankings
Neil Wagner provides the 'extra punch we need' - Shane Jurgensen
New Zealand's bowling coach was pleased with the efforts of the left-arm quick, who took three important wickets on day four at Hagley Oval
