Boks hooker Smit was ruled out of the game at Carisbrook after picking up a groin injury in the 17-8 defeat in Wellington the previous weekend.
Smit headed home to South Africa as a result of the injury, sustained in a dangerous tackle by Brad Thorn that earned the New Zealand lock a one match ban, and will also be missing from next weekend's game against Australia in Perth.
But Matfield said Smit was never far from the thoughts of the Springbok players and had played a significant part in the 30-28 triumph that ended a 10 year drought for the South Africans on New Zealand soil.
"I've always said that a captain is much more than what you do on the field and John helped us to put a lot of things in place over the last four or five weeks," said Matfield.
"That's what carried us through and helped us at the end, the things John left behind. He left us a great speech before the game and I think that really lifted the guys.
"He's part of this win just as much as we are."
Matfield has now set his sights and adding the Tri Nations title to the Webb Ellis Trophy and truly believes his side is right back in the hunt for the title they last won in 2004.
The giant lock was able to see his side ease their way back in front with four minutes to play thanks to a wonder try from scrum half Ricky Januarie and a cool conversion from the Boks' third goalkicker of the night, Francois Steyn.
"We were very proud of winning the World Cup last year, but I told the players we will be World Cup champions for the next four years and said we now had to focus on winning the Tri Nations," said Matfield.
"We are very glad to have won this game because it keeps us in the Tri Nations. From here we can move it forward.
"We now need to focus on our next game against Australia. That game is going to be just as hard as this one and they will give us different challenges."
Matfield admitted to feeling "worried and disappointed" when he was sent to the sin-bin by Aussie official Matt Goddard.
"Luckily we had players there - we had Jean de Villiers there, who was a great captain, and he got the guys to stick to the game plan. We showed great character and we came through," added Matfield.