Australia won their fifth consecutive game after opening their end-of-year tour with a 32-23 win over Japan on Saturday.
Not since October 2015 had the Wallabies enjoyed a five-game winning streak but they ended that drought by holding off Japan in Oita.
Despite a disappointing second half, Australia snapped their run of five straight Tests without a win away from home, having outscored Japan five tries to two.
The Wallabies – winners of all five previous encounters against Japan by an average of 39 points per game – raced out to a 14-3 lead on the back of tries from Tom Wright and Jordan Petaia before Lomano Lemeki hit back for the hosts.
Taniela Tupou added to Australia's lead early in the second half and after Lemeki landed himself in the sin bin for a shoulder charger, Robert Leota also crossed over to make it 27-13 with 28 minutes remaining.
Just as Dave Rennie's men looked as if they would run away with victory, Japan closed within a converted try in pursuit of their first win over the Wallabies.
But Australia – who benefited from two conversions and a penalty from Quade Cooper – withstood some immense pressure on the road to stretch their unbeaten streak.