Australia's women will play Russia in Monday's Canada Sevens Cup quarter-finals after finishing day one undefeated and on top of their pool.
An Ellia Green double has helped Australia to a 29-14 win over Canada and top spot in Pool C on day one at Langford.
in a see-sawing encounter, both sides had chances to seal the win but is was the Australians who ultimately made the most of Canada's errors in a gripping match.
It was a bruising clash between two of the circuit's powerhouse sides with Canada notching the first score through Julia Greenshields in just the first minute.
Australia dominated territory after that and initially Canada's relentless defence and some ill-discipline from the Aussies kept them off the line but eventually
In a marathon first half that went almost nine minutes, Australia turned a super Caslick try-saving tackle into a pivotal try for Evania Pelite just on half-time.
it looked as if Canada star Ghislaine Landry was going to give her side the advantage at the break but Caslick brought her down and Australia turned the play on its head, with Pelite eventually finding a gap.
Things only intensified in the second half and despite Australia's best efforts, Bianca Farrella powered over with just over four minutes to go to draw level with the Aussies.
Coach John Manenti had kept speedster Ellia Green on ice in the first half and that extra rest paid off as the powerful winger burst down the left edge to snatch the lead back for Australia in the 11th minute.
A Landry fumble opened up the opportunity for Australia to score again, through Emma Tonegato, and the reigning World Series champs had their biggest lead of the match.
Canada had a late chance to attack but the desperate Aussies stuck their tackles and put all the pressure right back on the hosts, and Green iced the game with a length of the field try.
Australia will play Russia, the second best third-placed side, in Monday's quarter-finals at 3:24am AEST.
Significantly, Australia is also on track to cross over with France, who are sitting 10 points behind the Aussies on the overall series standings.
Should both sides progress through the quarter-finals, a win over France would all but secure Australia an Olympic spot and a top four World Series finish.
EARLIER: The Aussies had an early scare against Brazil, conceding the opening try in the first minute of the match but that was the only score the Brazilians would notch in Australia's 43-7 win.
Ellia Green had a double in that victory, responding to that first Brazil try with an impressive solo effort almost immediately, and notching another in the eighth minute.
Pelite scored Australia's second and set up Charlotte Caslick for the side's first as they began to take control in the match.
Second-half tries to Sariah Paki, Emma Sykes and Yasmin Meakes sealed the win for Australia ahead of a crunch final pool game against hosts, Canada.
Earlier in the day, Aussies opened with a victory over Ireland in their first match of the tournament, sending a statement with a 33-5 win.
Alicia Quirk opened the scoring for Australia, the first of five individual try scorers for the team to kick off their campaign.
Lily Dick had their second in a tight first half but it was in the second stanza that the Aussies really stepped things up.
Star trio Pelite, Caslick and Green all crossed in the final minutes to ice a huge win over Ireland, who have become one of the big threats on the circuit.
Australia 33 - Ireland 5
Australia 43- Brazil 7
Canada 14 - Australia 29