But it was the manner in which his young charges overpowered their more fancied opponents, South Africa, in the Final at George last Saturday, that really surprised the critics.

New Zealand beat hosts South Africa 24-17 in a show of brute force and sheer determination to give Tietjens his 50th victory as coach - on his birthday last Saturday.

Tietjens admitted that he thought his men would not last the pace against the more experience, fitter and faster South Africans in the Final - especially after the Springboks came back from 12-0 down at half-time to win 31-12 in the Final in Dubai a week earlier.

And he then opted to take the Boks on physically, rather than using a traditional expansive approach - despite the fact that the South Africans fielded a couple of "monster" forwards.

A "hugely proud" Tietjens said he certainly did not expect his team to win.

"But they played with a lot of guts and determination," the Kiwi mentor said.

"I had thought that we had emptied the tank in the semi-final and I didn't think we'd be able to compete for 10 minutes each way in the Final. But they [the players] dug deep and our defence was magnificent. We had to take them on physically," he said about his team's tactics against the impressive South African outfit.

"I suppose the motivating factor for us was the second half in Dubai [where the Boks scored 31 unanswered point]. I just had to say 'the second half in Dubai' and that was enough really," he said about how he motivated his team.

He also pointed out that the most crucial play of the Final was the first try - scored by Zar Lawrence in the first minute after the restart.

"We had to score first in the second half and we did that. We put them under a littler bit of pressure [with that try] and uncharacteristically they dropped a few passes.

"I thought it was because our defence was so good and we put in some good hard tackles. They [the tackles] paid dividends I and think the crucial steer was early in the second half ... we stole a ball and scored a great try from that."

He said the win in George set it all up for a magnificent tournament in Round Three, when New Zealand will be on home soil in Wellington on February 2 and 3.