The New Zealanders had qualified directly for the final after a tempestuous 8-6 win over world No.3 Argentina on Saturday night gave them nine wins from 10 matches.

The Argentinians secured the rematch after downing Japan 6-0 earlier yesterday, but couldn't match a focused Black Sox outfit at Rosedale Park in Albany.

New Zealand delivered a vastly improved defensive effort, despite missing Ben Enoka, suspended after he was ejected following an all-in brawl in Saturday's turbulent win.

Pitcher Josh Pettett delivered an impressive performance, conceding just two hits across six innings in an MVP-winning effort.

The Black Sox made the most of their chances, Cole Evans crossing on a fielding error in the bottom of the second before Campbell Enoka slammed a home run in New Zealand's next turn at bat.

Thomas Enoka crossed for the Kiwis' third on the back of a couple of Argentinian fielding errors at the bottom of the fifth, then the Kiwis wrapped up the game with six runs at the bottom of the sixth inning.

Jovaan Hanley, Alfons Oveinikovas and Jerome Haretuku added to the tally before Wayne Laulu slammed a game-ending home run which also brought in Campbell Enoka and Josh Harbrow.

New Zealand coach Mark Sorenson was happy with his team's improvement over the five-day tournament as they prepare to defend their title at the world championships in Canada later this year.

"We saved our best until last, and the exciting thing for me is I've seen what we can produce," he said.

"It's the sort of thing we've been working towards. We're making progress, we're heading in the right direction."

The Black Sox's only loss in the six-nation tournament was a 2-1 defeat by world No.2 Japan on Friday.