"It was quite messy towards the end. So we put our front liners back on."
Playing a fellow country team with a similar "nuggety attitude", Wanganui picked up three green cards around that 50th-60th minute period, but South Canterbury lost Dougal Gibson to a yellow card for a late tackle in the 54th minute, just when they went without a goalie.
"It was a pretty cool finish, big ups to the boys, they deserved to win," said Matthews.
"A couple of goals put the pressure on [South Canterbury]."
Charnce Tangiiau and Connor Managh scored field goals in the 13th and 18th minute to set the tone, and then in the second half Ben Havord converted a penalty corner in the 43rd minute with a Ryan Bayler field goal following two minutes later sealed the deal.
Blake Hoskin (nine) and Charlie Sutton (eight) didn't get to add to their impressive goal tallies, while the hard-working Finnegan Murphy was named team MVP.
Matthews had been involved with the 2017 team under coach Andrew Spence that finally won the U15 Championship after years of coming close, which was accomplished on the back of rock-solid defence by not giving up a single goal.
However, the 2018 played with speed and skill, with Matthews comparing their passing abilities to the same level of her Central age group teams who have played in the NHL.
"It's been one of the most exciting teams I've had the chance to work with."
As Hockey Wanganui chief executive, Matthews has been given dates for the 2019 National Championships, but all eyes are on November where the Hockey NZ decision on the fate of both Central and the Northland associations will be made.
As well as Wanganui's success, Northland finished third at the National Premiers boys competition in Christchurch, while home town team Hawke's Bay came third at the Premier girls tournament in Napier.
Matthews said the Under 15 teams success means the Wanganui Under 18's are looking strong, while Central age group teams and players have also been making their presence felt on the national scene.
"The results the Central region teams are getting, people are starting to think, 'what are [Hockey NZ] doing'?"
Unfortunately, Canterbury B continues to be the thorn in the side of the Wanganui Under 15 girls team, beating them 2-0 in the National Championship final in Carterton, which made it a provincial double as Canterbury A won the Premier tournament in Napier.
Abby Mason in the 19th minute and Niamh McKenzie 32nd minute got the goals for the champions, who also picked up two green cards, as did Wanganui.
"The girls played really well, but we lost," said coach Jan Dixon.
"A shot hit the post, and stuff like that.
"It was a pretty good team effort."
Skipper and team MVP Olivia Smith just missed a shot, while Charlotte Baker was the one to hit the post.
Margy Hazelhurst worked hard, just as she had all tournament, while Nicole Parata and striker Jane Abraham had good games.