The Wallaroos are urging fans to keep the faith after showing vast improvements in a series-opening 33-14 Pacific Four loss to classy Canada in Sydney.

Unbeaten against the Wallaroos since 2014, the Maple Leafs again proved too powerful and precise in a bruising forward battle at Allianz Stadium on Saturday.

All five Canadian tries came from the front row as the Wallaroos failed to contain the visitors' deadly driving maul.

Jo Yapp's Australian side, though, were left heartened after showing significant strides since a last-up 45-7 defeat to Canada in Ottawa 10 months ago.

Only poor handling and an inability to bring electrifying wingers Maya Stewart and Desiree Miller into the game enough stopped world No.5 Australia from seriously threatening the fourth-ranked Canadians.

"Lots of positives to take away," Stewart said.

"Definitely glimpses of what we can do out there.

"Just some handling areas, some basic stuff. We'll crack that front door again and unlock our edges.

"There's only more in the tank, so stay with us."

The Wallaroos were unable to contain Canada's maul early, with hooker Sara Cline and prop McKinley Hunt both cashing in inside the opening 10 minutes.

Hunt's finish came off an incredible 22-metre drive.

Down 12-0 in less than as many minutes, the Wallaroos had to dig deep to stay in the contest.

And they did.

Powerhouse flanker Siokapesi Palu looked to have grabbed Australia's first try, after storming on to a nice inside pass from Stewart, only for the video referee to pick up a knock on earlier in the lead-up.

There was no denying Tania Naden shortly after when the Wallaroos dealt Canada a shot of their own medicine with a rolling maul strike off a clinical lineout win from Katie Leaney.

Cline's second try on the half hour, again off Canada's maul, earned the visitors a 19-7 lead at the break.

Hunt's second straight after halftime shot the fourth-ranked Maple Leafs out to a 19-point advantage.

Again, the Wallaroos hit back, this time with a penalty try after Canadian winger Maddy Grant knocked down Georgina Friedricks' pass that would sent prop Brianna Hoy over for a certain five-pointer.

Alas, instead of taking advantage of their one-player advantage with Grant in the sin bin, Australia conceded a fifth try to find themselves trailing 33-14.

Despite showing admirable resistance in the final 20 minutes, the Wallaroos were unable to peg back the deficit.

Still, skipper Michaela Leonard believes the Wallaroos will only emerge stronger for next Saturday's clash with the USA in Melbourne.

"Obviously disappointed in that result out there," Leonard said.

"Props to Canada. They came out and they played a physical fast game, which we expected and we saw that with Maya and Desiree Miller on the edges.

"It's just going back to fixing our execution a little bit on our detail and bringing a little bit more physicality next week."