"Workhorse" is how Brendon McCullum described Neil Wagner before the Test. New Zealand then strapped four seamers to their plough on a generally lifeless Dunedin surface, but each quick had his specific role. Tim Southee and Trent Boult are the shiny-coated thoroughbreds, operating from sleek run-ups and liquid velvet bowling actions. In comparison, Wagner is one of those plodding, thick-set horses with fur around their ankles and a perpetually morose expression. He was left in the stable during New Zealand's recent tour of Australia. This may partially explain the morose look. He also lives in Dunedin.

On the fifth morning, when Sri Lanka began to surge - Dinesh Chandimal slap-happy behind point, Angelo Mathews turning the strike over - Wagner began to till a furrow on leg stump. In his second over of the day, a short one at Mathews' throat was ducked under. The next one took the shoulder of the bat and whistled by leg gully for four.

It was having got the batsman fearful of two close catchers on the legside that Wagner slipped in the surprise. Mathews attempted to pad away the full, swinging delivery next over, and wound up granting safe passage to the ball, through the arch of his splayed legs. He would later say the ball hit his pad and simply "rolled" into the woodwork. This is like saying the Titanic merely brushed the iceberg; that Poland had just been tickled by the Nazis. The only things actually rolling was middle stump, which had been uprooted, and maybe fans watching the dismissal, splitting their sides.

"I thought it was beautifully set up," Brendon McCullum later said of that breakthrough. "It was a sustained period when Wags was trying to go in around the rib cage, to try and get Angelo off the ball. Angelo's such a world-class player, you can't just run in and try and hit off top of off stump to him because he's so adaptable and he's got such a strong defence as well.

"It was a plan we wanted play out, and when he started walking across his stumps a little bit, Wags decided that at some stage he was going to try and bowl the miracle ball to hit the base of leg stump. In the end it split his defence."

After that breakthrough, Wagner's furrow grew to a channel, then a river, which Sri Lanka were washed out to sea in. Wagner helped muzzle Dinesh Chandimal, before he was out at the other end, padding away a delivery from Mitchell Santner. Kithuruwan Vithanage chanced his blade for 38 balls, but was gone before lunch. Boult came back to knock out a feisty Sri Lanka lower order, yet it had been Wagner who unlocked the victory.

New Zealand were made to labour for their wickets throughout the Test, so in many ways it fit that a man such as Wagner made the pivotal play on day five. In all, they bowled 212.3 overs in the Test, without a specialist spinner. The new-ball bowlers swung it a little, but Doug Bracewell delivered economy, and Wagner nearly bowled himself into his hometown dirt. The effort was collective. Southee picked up New Zealand's best figures in the innings, with 3 for 52, but to find a less impressive "best analysis" for a New Zealand bowler in wins, you would have to go back to 2009.

"I thought Doug bowled absolutely brilliantly throughout the test match and all through Australia as well," McCullum said, of Bracewell, who also had two catches spilt. "He just hasn't got the rewards at the moment, but I'm sure he will get them soon."

In their last home series, also against Sri Lanka, New Zealand's big-name players dominated. McCullum plundered 195, Boult and Southee scythed through the top order, and Williamson finished with the series' highest score. In this Test, the hosts' lower profile players have made critical contributions. Mathews is the owner of one of the world's best defensive techniques, but on day five, the workhorse brought down the barn door.

Andrew Fidel Fernando is ESPNcricinfo's Sri Lanka correspondent. @andrewffernando