All Blacks captain Richie McCaw believes his team's Rugby Championship victory has proved that they are worthy world champions.

All Blacks captain Richie McCaw believes his team's Rugby Championship victory has proved that they are worthy world champions.

McCaw's team recovered from conceding an early try against Argentina by running in seven to triumph 54-15 at Estadio Ciudad de La Plata on Saturday and take an unassailable nine-point lead over second-placed South Africa with one round to go.

A surprisingly easy victory stretched their winning run to 15 matches - three short of the record held by Lithuania - with Tests in South Africa and Australia next month before a November tour of Europe.

"It was one of our best performances this season," captain McCaw said of the record win by the All Blacks in seven Tests on Argentine soil.

"When we started out in the Championship the goal was to put last year behind us. We have got the tag of world champions and we needed to play like them," he told a media conference.

"To secure the Rugby Championship was obviously the big goal and it is nice to be able to do that. We gave a performance the guys are pretty happy with. It is the manner in which we did it that was so satisfying."

Coach Steve Hansen said his team still needed to improve after its pace and power pummeled the Pumas.

"We can pat ourselves on the back and enjoy the moment, but there are still areas to improve on and one of them in the connection between the forwards and the backs.

"To be able to attack like that you must have a platform to work off so the forwards can be very proud. Our rucking was also much better than against South Africa."

Argentina coach Santiago Phelan said his team made too many defensive errors as they conceded only one try less in La Plata than they did in four previous Championship Tests in Cape Town, Mendoza, Wellington and on the Gold Coast.

"We set out to try and do things better with the ball, but took a step back in our defensive organisation. Some of the tries stemmed from our mistakes - others from the effectiveness of the All Blacks."

Martin Landajo, an impressive scrumhalf who scored the brilliant opening try of the game, said New Zealand defended and attacked so well, but believes a first Championship win is possible when they host Australia in Rosario.