Mallett called the 31-27 result "a marvellous match and a good contest".
He continued: "The Boks were so competitive and came within an ace of winning. Heart-stopping stuff.
"It was so similar to the way they played their last five Tests. I remember writing at the beginning of the winter that Jake White would have to decide what sort of game plan he wants."
Mallett believes the Boks have done exceptionally well in this year's series even though the Tri-Nations title may now slip away.
He said: "Overall, it's been a splendid Tri-Nations, with great performances by the Boks. New Zealand will be too strong for Australia on Saturday, but SA defended their title well and have come through a series of Tests with much credit.
"It's difficult to single out one player from a team that has played so well collectively.
"The emergence of Bryan Habana as a try-poacher has been important, the blossoming of the new centre pairing was excellent and Rickie Januarie has proved a revelation.
"He's a little guy but incredibly physical and had a hand in all three tries due to his pressure play.
"Looking at the pack, the emergence of Gurthro Steenkamp, John Smit's captaincy and play and the form of the lock pairing, which can match any in the world, have been highlights.
"There's a well-balanced back three, with Schalk Burger having improved his discipline. I have no doubt the Boks can look forward to the years before the World Cup with great heart."