"We've worked hard for it since 2009," said coach Eddie Kohlhase, who became the first man to win a world title as player and coach.
"The team has just believed, really. We stuck to our processes and systems and just worked very hard together. I'm very proud of them."
New Zealand's rags-to-riches tale over the past month was exemplified by their captain. Casley required surgery after badly injuring his throwing shoulder last year and the infielder's involvement was still in doubt as recently as a fortnight ago.
He has seen very little time in the field during the tournament, serving predominantly as the designated player, but made his mark with the bat when it really counted. After delivering a vital second run in Saturday's victory over Venezuela to qualify for the final, Casley struck again yesterday in the third inning with the score locked at 1-1.
"Captain courageous, really," Kohlhase said. "He shouldn't even be there with that shoulder injury. But credit to the physios and medics to getting him out there.
"Big players step up in big games. He probably typifies the belief in this team and what we were trying to work on the whole 10 days."
Casley said the hit made up for all the weeks of rehab and doubt, even if he wasn't searching for such a defining contribution when standing at the plate.
"I wasn't looking to hit a home run - I was just looking to make solid contact after I struck out the first time. I was just happy to put good wood on the bat and get one out."
So were his teammates as, with Manley in imperious form on the mound, Casley's deep ball always looked likely to be the game-winner.
Venezuela - who beat Australia to make their first final and were playing to honour late president and softball fan Hugo Chavez - stole into the lead in the first inning before Manley took control.
Catcher Patrick Shannon's solo home run in the second tied the game and some sparkling plays in the field ensured the South Americans never threatened to work their way back into the contest.
Shannon announced his retirement immediately after the game and a number of other senior players are unlikely to return when the Black Sox attempt to defend their crown in two years.
"We spoke a little bit about that this morning," said Casley, confirming he intended to continue. "Every time we put on the black shirt we look at it as it could be our last game. You just never know who's going to be back and who's not."
For those who are unlikely to return - such as Jarrad Martin and Thomas Makea who tied Mark Sorenson's record with a fourth world championship - it was a fitting way to end a golden generation.
Black Sox 4
Venezuela 1
Six of the best Black Sox world championships
1976 at Christchurch (shared with USA and Canada)
1984 at Michigan, USA
1996 at Michigan, USA
2000 at East London, South Africa
2004 at Christchurch, NZ
2013 at Albany, NZ