Australia made a solid start to their Rugby World Cup Sevens campaign by downing Portugal 24-12 in their first Pool match in Dubai.

Richard Kingi opened Australia's account with a try and kicked the conversion to make it 7-0 at the break.

Australia found their rhythm in the second half with Henry Vanderglas, Damon Murphy and Brian Sefanaia all running in five-pointers, while Portugal could only manage 12 points.

Coach Michael O'Connor said he was relieved the Australians got a way with the win.

"Portugal is a good side, the last time we played them under 12 months ago they beat us quite comfortably in London," O'Connor said.

"They have done very well in recent tournaments and it was never going to be an easy game for us.

"The players showed a lot of commitment and courage in defence. They really didn't have much form in the first half."

Australia next meet Ireland on Friday and play their last pool match against Samoa later that evening.

In other results, France surprised the United States 26-17, New Zealand hammered Italy 42-0 and South Africa posted a 26-5 win over Japan.

Fiji led Georgia only 12-10 at halftime then pulled away to win 26-10 to join New Zealand as the only teams to pass 1,000 points in World Cup Sevens history.

Tonga cruised past Arabian Gulf 19-0, Canada upset Scotland 33-14 and England, the 1993 champion, dispatched Hong Kong 42-5.

South Africa's first up effort didn't impress coach Paul Treu. He was unhappy with the five points his side conceded.

"You can't afford to do that at this level," Treu said.

"The teams are competitive and it can all go down to those five points in the end. I am disappointed that we allowed them to score the try.

"We'll need to tighten our defence for Friday's matches."

The pool winners and two best second-placed teams advance to the quarter-finals.

The inaugural women's competition starts on Friday.

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