Hansen issues warning after All Blacks win Wallabies 'prizefight'

Steve Hansen warned New Zealand must be ready to land a knockout blow on Australia after flexing their muscles in a Bledisloe Cup "prizefight" at ANZ Stadium on Saturday.

The world champions trailed 6-0 just before half-time, but Aaron Smith rounded off a slick move to reduce the deficit to a point at the break and the All Blacks turned on the style in the second period to win the Rugby Championship opener 38-13. 

Impressive debutant Jack Goodhue, Beauden Barrett and Brodie Retallick went over before Waisake Naholo added a late double following a five-pointer from Jack Maddocks on his Wallabies bow.

All Blacks head coach Hansen felt the defending champions reaped the rewards for turning the tide in the first half.

"We thought the first half was like a prizefight, both teams were testing each other out," he said.

"They [Australia] probably had their moments in the first 20 minutes and made us make a lot of tackles. Then it was our turn to have our moments and whilst we didn't capitalise like we would have liked to have in that 20 minutes we certainly made them work hard.

"We managed one just before half-time and then after half-time we came out and hit the boards running and that was the hard work we had put in over the last 20 minutes of the first half."

Hansen had a word of caution as he looked ahead to another clash with the Wallabies at Eden Park next weekend.

"You come to Sydney and you expect an explosion and we sort of got a different type of an explosion this time," he added.

"We haven't done anything tonight other than get the right to put one hand on the cup and we've got to go back next week, work hard and earn the right to put the other hand on it."