"We're happy with the first win," said Matfield, who made his 78th appearance in Sprinbok colours in front of more than 74,000 spectators at the Millennium Stadium
"We came over here to get three wins and we knew this was going to be a very tough one. We came here knowing we were playing the Six Nations Champions at home, in the middle of their season, so we always knew it was going to be tough."
The Boks established a 17-point lead by the 50th minute on Saturday afternoon but Matfield and co had to work hard to withstand an impressive comeback that saw Wales come within a single score of the World Champions.
"They came out, especially in the second half, carrying the ball and playing well. It was a pity we couldn't get our hands on the ball," added Matfield.
"I think we made too many errors and gave away too many penalties so weren't able to get into the game in the second half. I think that was probably our biggest problem. If you make that many mistakes and are in your own half and under pressure all the time, then they capitalise on it.
"We're happy with the win - we defended well and we didn't let them score a try - although there is still a lot of work we can do and I don't think it was our best performance."