Rio 2016 Olympics: Matildas downed by Canada in women's football opener

In a terrible start to Australia's campaign at the Rio Games, the Matildas copped a goal in just 21 seconds in a draining defeat at Sao Paulo's Arena Corinthians on Wednesday (Thursday morning AEST).

The first Australians in action at the Games were rocked by a defensive blooper which gifted Canada's opening goal.

Laura Alleway sent a sluggish sideways pass towards her defensive counterpart Alanna Kennedy, who didn't sense a snooping Canadian captain Christine Sinclair until too late.

Sinclair intercepted and, with time and space, charged at goal before arrowing a poised pass to teammate Janine Beckie, who tapped it in from barely one metre out.

The Australians spent the rest of the Group F fixture huffing and puffing but couldn't blow Canada's goal down, until letting in another goal about 10 minutes from fulltime.

Canada had just 10 players from the 18th minute after defender Shelina Zadorksy was marched off with a straight red card for grappling with Michelle Heyman when the Matildas forward was tracking towards goal.

The Matildas recorded 22 shots to eight - Elise Kellond-Knight came closest in the 20th minute when a sweet long-range free kick struck the crossbar.

But their need to attack backfired spectacularly in the second half.

Matildas goalkeeper Lydia Williams, in the 73rd minute, kept her nation's hopes alive by saving a penalty after a referee's blunder - Caitlin Foord was ruled to have hand-balled in the box but the ball struck her hip.

Just seven minutes later, the Australians were on another attacking sortie when Canada pinched the ball and sent it sailing from their danger zone.

Custodian Williams was on the charge and just nearing the halfway line but Canada's Sinclair got the ball first and, from almost 25 metres, launched a shot into a vacant net.

The Australians next meet Germany in Sao Paulo on Saturday from 1800 (Sunday 7am AEST ) before a last group game against Zimbabwe three days later.

AAP