Australia hooker Tolu Latu scored two tries in five minutes as the Wallabies came from nine points down in the second half to beat Fiji 39-21 and escape a huge upset at the Rugby World Cup on Saturday.
Fiji haven't beaten Australia for 65 years -- a run of 17 winless games against the two-time world champions -- whose fans dominated the crowd of 36,482 at the indoor Sapporo Dome.
But that did not stop a physical team featuring several of Fiji's Olympic Sevens gold medallists going ahead 21-12 against the 2015 runners-up four minutes after half-time.
Australia, rattled by Fiji's powerful running, eventually made their forward dominance count thanks to unlikely try hero Latu's double following the match-changing entry of scrum-half Will Genia.
Tries from Fiji-born backs Samu Kerevi and Marika Koroibete then sealed Australia's comeback win.
Wallaby coach Michael Cheika said he was "not going to complain at all" about the result against the "dangerous" Fiji.
"We know them very well, their players and that's what we expected. Probably didn't expect to be as far behind!" he admitted.
Australia almost scored from the opening kick-off when Reece Hodge charged down an ensuing clearance kick, only for Fiji to scramble the ball clear.
After Australia-born Fiji fly-half Ben Volavola knocked over an early penalty, a box-kick from Wallabies scrum-half Nic White allowed Fiji to counter-attack.
Fiji right wing Josua Tuisova bounced off Hodge and burst through Christian Lealiifano's tackle before releasing flanker Peceli Yato for a try in the right corner.
Australia eventually made their setpiece play count in the lead-up to an 18th-minute try for Hooper, who drove over after the Wallabies pushed Fiji off their own scrum.
Fiji suffered a setback when Yato went off with concussion in the 26th minute after what appeared to be an illegal no-arms tackle by Hodge.
Captain Dominiko Waqaniburotu said they had asked New Zealand referee Ben O'Keeffe to refer the incident to television match official Rowan Kitt but no action was taken despite World Rugby promising a crackdown on head-high challenges.
- Flamboyant dive -
Two Volavola penalties extended Fiji's lead to 14-7.
Australia's forwards then earned a penalty that led to an attacking line-out and, after the ball was worked across field, Hodge went over for a 36th-minute try in the right corner but Lealiifano could not nail the conversion.
Fiji led by two points at half-time and they were nine in front four minutes after the break.
After a poor Australia pass sailed over Lealiifano's shoulder, Fiji centre Waisea Nayacalevu gathered it up and ran in from nearly half-way before flamboyantly diving between the posts.
Hodge's penalty cut Fiji's lead to 21-15 and it was no surprise when Cheika brought veteran scrum-half Genia off the bench in a bid to regain control.
Playing the ball close from a succession of line-outs, Latu eventually went over from a maul for a 57th-minute try to cut the deficit to one point.
Hodge missed the conversion but Australia finally went ahead in the 62nd minute through an almost carbon-copy score by Latu.
Matt Toomua, Australia's third goalkicker of the match, missed the conversion.
But Kerevi put the result beyond doubt in the 68th minute after the Wallaby pack drew in Fiji's forwards with Toomua kicking the conversion.
Australia completed their win with a setpiece move off a line-out that ended with Koroibete beating his man for a well-worked try.
Concussion rules mean Fiji will be without Yato for their next match against Uruguay in Kamaishi on Wednesday, with Australia playing fellow Pool D favourites Wales in Tokyo a week on Sunday.