Hamilton, just two games into life as the Wallaroos captain, put in an inspirational performance to earn her second player-of-the-match honour in as many weeks and help Australia secure a 46-3 win and historic clean sweep of the two-Test series.

She scored the home side's first try and backed it up with two more at the end of the match but also led with her ferocious work rate, clocking more than 200 run metres to keep Australia on the front foot in front of a crowd of 3391.

She was supported by a stellar cast, including former captain Liz Patu, NSW prop Emily Robinson, sevens star Mahalia Murphy and Cramer, the livewire Queensland winger and goalkicker who contributed a total of 16 points, including a try, in her maiden start in the gold jersey.

"In the change room, before the girls came out, we said, 'Let's make a statement' and I think they did," coach Dwayne Nestor said.

"They made a really good statement in that first half, we probably fell asleep a little bit in that second half but then [we] finished [it] off."

Although the scorelines in both Tests were one-sided (34-5 in Newcastle last week), this is the best preparation the Wallaroos have enjoyed outside a World Cup year for their upcoming two-Test series against world No.1s New Zealand.

"That was great preparation for us, really good preparation," Nestor said.

"You look at last year and you wish we'd had the same preparation before we went to the Black Ferns. But to have that this year is awesome, and the program going forward next year [Australia will be part of a four-nations competition] is even better."

Cramer put Australia on the scoreboard first with a penalty goal and then converted her captain's first try in the ninth minute to make it 10-0.

Japan held on to the ball for long periods in the first half but could only convert the territory into points once, through a penalty goal from fullback Minori Yamamoto in the 17th minute.

A double from Murphy book-ended Cramer's maiden Test try and Australia led 27-3 at the break despite Cramer narrowly missing the conversions for Murphy's tries in the 20th and 38th minutes.

Australia's physical dominance told early in the second half, not least when former captain Patu was injected off the bench. The Queensland hooker cleaned up Japan halfback Moe Tsukui and bulldozed her way through red-and-white defenders on countless occasions.

Samantha Treherne had a 51st-minute try disallowed with a pass ruled forward from Hira-Herangi.

Three minutes later Cramer was sent to the bin, handing Japan their best attacking chance of the match.

They worked hard and it appeared to have paid off when blindside breakaway Misaki Suzuki appeared to touch the ball down in the corner, only for replays to show she had lost control of the ball over the line.

Australia kept coming, Hamilton scoring twice in five minutes and Millie Boyle adding the seventh in the 74th. Cramer converted the last two tries to close out the match 46-3, earning praise from Nestor for holding the Sakura scoreless in the second half.