Sir Graham Henry believes the All Blacks are perfectly set up to successfully defend the Webb Ellis Trophy.

The 2011 World Cup-winning All Blacks coach was at Twickenham for the 20-18 semifinal clash and felt the Springboks extending New Zealand all the way to the wire was the best possible preparation for the final against Australia or Argentina.

Henry felt the close call was needed after the big quarter-final win over the French the week before.

"It will be great for next week because they didn't play particularly well but they did the job," Henry told Newstalk ZB sports host Tony Veitch after the game.

"I was concerned because we hadn't played well in the first half, we'd kicked a lot of ball away, we didn't look sharp, our scrum was under a bit of pressure and we had given a lot of penalties away. There's lot to work on but psychologically that's good for next week.

"At the end of the day, we were the better side. We scored two tries to none. The Springboks never looked like scoring tries. It was just that we kept them in the game by giving away penalties which was a bit irritating.

"They will be a bit disappointed about how they played but they will be delighted they are in the final and they will play well next week, there's no doubt about it.

"I've got a feeling this game will do them a huge amount of good. Last week's game against the French, in actual fact, was actually pretty counter-productive. They won too easily. People are human and when you win easily you probably get a wee bit of an inflated opinion of your own ability and it just gives you a false sense of security.

"This game was ideal. Winning the game and surviving, they will be in good shape mentally for next week. "

Henry nominated three key incidents that helped swing the semi-final New Zealand's way. They were Dan Carter's sharply-taken drop goal in the second half, a "critical" Sam Whitelock lineout steal off Victor Matfield with eight minutes to go and Boks winger Bryan Habana prematurely charging an attempted conversion from Carter which resulted in referee Jerome Garces ordering a re-take which the All Blacks' No. 10 nailed.

"Bryan've got two points there - and looking back now, two points was the difference at the end of the game," Henry said.

The coaching knight predicted Australia would beat Argentina in tomorrow morning's other semi-final, setting up a dream showdown against the All Blacks.