All Black captain Richie McCaw admitted Sunday that the bruise below his left eye came from teammate Owen Franks.

Quizzed about the facial swelling after a 32-16 Rugby Championship triumph over South Africa at Soccer City, the 112-cap New Zealand flank said tighthead prop Franks was responsible.

"It was friendly fire I'm afraid," McCaw said.

"I have Owen Franks to thank for this one.

"This game certainly doesn't make you any prettier I'll tell you, but when you sit in the changeroom with the men that you go out to battle with and have a cold one it is pretty satisfying," he admitted after New Zealand completed the Southern Hemisphere championship with six victories.

The world champions were forced to come from behind to seal their 16th consecutive Test win, and they rose to the occasion admirably, scoring 20 unanswered points in the second half.

It was McCaw's 100th victory in an All Black jersey and the legendary skipper said that playing in front of over 80 000 people had been a special experience.

"It is a helluva stadium to play in and you love playing in these Test matches because they are brutal and you have got to be on your game and that is what it was like tonight," he said.