New Zealand 441 (McCullum 195, Neesham 85) and 107 for 2 beat Sri Lanka 138 (Boult 3-25, Wagner 3-60) and 407 (Karunaratne 152, Boult 4-100, Southee 4-91) by eight wickets
Scorecard and ball-by-ball details
It had to be black magic. Tim Southee and Trent Boult were swinging a 70-over old ball on the fourth morning. Both ways. Their skill accounted for 13 of the 20 Sri Lankan wickets and confirmed Brendon McCullum's Boxing Day assault as match winning. Christchurch witnessed New Zealand's fifth victory in 2014, marking it their best year in Test history.
A target of 105 appeared straightforward, but Sri Lanka created a few nervous moments for New Zealand along the way. A fluent Tom Latham was undone by a ripping turner from debutant offspinner Tharindu Kaushal and Hamish Rutherford was surprised by Shaminda Eranga's extra bounce and lobbed a catch to gully.
Sri Lanka strived hard for further inroads. Ross Taylor and Kane Williamson, though, were resolute and secured the Test in the seventh over after tea on the fourth day.
The visitors had begun the day 10 runs behind and with five wickets in hand, and their best chance was if their captain Angelo Mathews could shepherd the tail. But even he was unprepared for the bouncer from Southee, feathering an edge to the keeper off a front-foot pull early in the morning.
Kaushal, the night-watchman, managed a couple of pleasing strokes through square leg and cover off the front foot before a short ball in the off-stump corridor did him. He was caught in two minds and before he could pull the bat away, the edge flew to Mark Craig at second slip to give Southee his first strike of the morning.
Dhammika Prasad was reluctant to get in line for most of his 17 balls and was not ready when Southee sprung the trap with the fuller length - twice. Ross Taylor grassed an absolute dolly, but before his face could grow red another came his way and he caught it.
Sri Lanka did well to bat until lunch and their final-wicket pair even forced the umpires to take a half hour's extension. The lead was 17 when Mathews was dismissed, but Eranga and Suranga Lakmal conjured 59 runs off 57 balls. Their clear-the-front-leg-and-swing tactic frustrated New Zealand as they either watched the ball skirt past the outside edge or skim to the cow-corner boundary. Boult broke through and earned himself and his fellow bowlers some well-deserved rest after 196 testing overs across the two innings.
Alagappan Muthu is a sub-editor at ESPNcricinfo