New Zealand captain Richie McCaw scored twice within the first seven minutes to inspire the World Cup favourites to a 76-14 win over Italy in their opening Pool C match on Saturday.

Right wing Doug Howlett completed a hat-trick of tries and there were also scores to left wing Sitiveni Sivivatu (two) centre Mils Muliaina, lock Chris Jack and flanker Jerry Collins (two).

McCaw scored his first try after only 64 seconds and the All Blacks romped to 43-0 before the Italians finally got on the board with an intercept try to left wing Marko Stanojevic just before halftime.

Centre Mirco Bergamasco scored a late try for Italy after a more spirited second half display by the Six Nations side.

New Zealand coach Graham Henry said his side's overwhelming victory vindicated his decision not to schedule any warm-up matches after the Tri-Nations.

"We got a lot out of the game, more than the scoreline indicated and it proved that we were right not to overdo it before coming here," Henry said. "The decision making in the first 30 minutes was precise and the guys played pretty well.

"We got a little untidy in the set-piece as the game wore on, but in general we were very pleased."

Twice-champions Australia predictably over-powered Japan 91-3 in the Pool B match. Flanker Rocky Elsom scored twice within eight minutes to help the 1991 and 1999 champions to a 23-3 halftime lead. He added a third a minute after the interval as Australia ran riot with 13 tries.

Defending champions England struggled to an unimpressive 28-10 win over the United States in Pool A.

England led 21-3 at halftime thanks to late tries by wing Jason Robinson and flyhalf Olly Barkley. But they added only one further try after the interval, scored by flanker Tom Rees.

Replacement forward Matekitonga Moeakiola replied for the United States.

Playing today: 2 p.m. Wales vs Canada; 4 p.m. South Africa vs Samoa; 6 p.m. Scotland vs Portugal; 8 p.m. Ireland vs Namibia..