© David Becker/Getty Images

Australia and New Zealand have booked their places in the finals of the Las Vegas 7s tournament with two easy wins on the opening day of the tournament. Australia easily dispatched Scotland before sweeping aside Japan, while New Zealand looked on track to win their third consecutive leg with emphatic victories over Portugal and Russia.

Australia continued their great form from the Sydney 7s tournament dominating Scotland 26-0 in their opening game of the day. Australian flyer Henry Hutchison got on the board quickly with a well worked try from the Aussies as he dove over in the corner, before Sam Myers crossed for their second.

Wallabies star Quade Cooper made his long-awaited debut for Australia in sevens rugby, as he came on as a substitute with just under five minutes left in the second half, but his first few touches of the ball resulted in wayward passes as he initially struggled to adjust to the shortened format.

Australia still dominated play with captain Ed Jenkins and Tom Lucas scoring second half tries.

Australia dominated again in their second match, and while another "no look" pass from Cooper failed to go to hand in the later 33-5 victory over Japan, the Australians went over five tries with a double to speedster Greg Jeloudev, and tries to Ed Clark, Pat McCutheon and Allan Fa'alava'au.

It wasn't all bad news - Cooper did notch his first points against Japan with four conversions.

Meanwhile, reigning World Series champions Fiji suffered a shock defeat by Samoa in their opening game.

A last-gasp try by Savelio Ropati earned Samoa a thrilling 28-24 victory over their Pacific rivals in the most entertaining encounter at Sam Boyd Stadium, just off the Las Vegas Strip.

DJ Forbes© David Becker/Getty Images

New Zealand, were in cruise control as they powered past Portugal 42-7 and Russia 38-0 to take a stranglehold on Pool A. All Blacks sevens veteran DJ Forbes made a strong return after missing the Wellington and Sydney legs, scoring a try in their six try hammering of Portugal.

England had a poor day and came perilously close to being on the receiving end of an upset when they trailed Japan 19-5 with less than two minutes left in their Pool B opener. They battled back with two tries, however, the second converted after the buzzer by Tom Mitchell to secure a dramatic 19-19 draw.

There was to be no comeback in their second match against Scotland and Joe Nayacavou scored a late try to seal a 24-14 win in the final action of the day to put the English out of contention for the Cup.

Prolific winger Bryan Habana, South Africa's leading try-scorer in Tests with 64, made a successful return to sevens after a 12-year absence as the Springboks recorded lop-sided wins against Canada and Wales in pool D.

Carlin Isles, the "fastest man in rugby", and fellow speedster Perry Baker both showed off their raw pace as the United States notched a 19-12 win against Wales followed by an error-prone 26-26 draw with Canada in pool D.