The Wallabies have escaped with a 19-15 win over Japan at Tokyo's National Stadium in the first leg of the Spring Tour.
Joe Schmidt's side got out to an early lead courtesy of a try from acting captain Nick Champion de Crespigny.
However, the Eddie Jones led Brave Blossoms weren't deterred as they continued to turn Australia away despite having little possession or field position.
MORE: Carter Gordon opens up on Joe Schmidt relationship following Wallabies return
The Aussies were left short-handed in the second row when both Lukhan Salakaia-Loto and Josh Canham left the field with injury.
"Josh Canham obviously won’t be available next week and as yet I don’t have the full feedback on Lukhan Salakaia-Loto," said Schmidt in the post-match press conference.
"We might need to get some reserves dug out from Australia.
"With 13 changes and losing two locks early on it did become difficult for us."
Despite entering the contest as firm favourites, the Wallabies seemed content to just survive and advance given the circumstances of the match.
"We actually had to really roll our sleeves up and keep fighting for that one," said Schmidt.
"In those conditions, it’s just about what we managed to do.
"There’s nothing surprising about how competitive they were, how combative they were.
"I really admired the grit."
Australia will need to regroup and recover as they travel to London to face an England side who have won seven Tests on the trot.