Sam Kerr sparks Matildas' rout of Japan at Tournament of Nations

Sam Kerr has fired the Matildas to a second consecutive win at the Tournament of Nations, scoring a hat trick in the first half of Australia's 4-2 defeat of Japan.

The West Australian scored her first international hat trick as the Australian women's soccer team came from behind to defeat their great regional rivals.

Kerr was irrepressible, combining pace and lethal finishing.

The win -- Australia's heaviest over the Nadeshiko in 32 years -- followed the Matildas' first-ever defeat of world champions the United States on Friday.

While the American triumph came from an all-round team effort, San Diego saw the Sam Kerr show as she brought her strong club form to international level with devastating effect.

Japan striker Mina Tanaka opened the scoring when she chested home a cross to put her side ahead after six minutes.

On 11 minutes, Hayley Raso showed lightning pace to break free down the right, cutting back to an unmarked Kerr to tap home an equaliser.

Five minutes later, the Australian No. 20 turned her marker before unleashing a curled finish past Sakiko Ikeda to put the Matildas ahead.

As half-time loomed, Kerr used her pace once more to complete the hat trick.

The Perth Glory striker won a header in the nick of time and raced on to her own work to score a one-on-one at the second attempt before celebrating with a handstand and backflip.

Australia maintained the rage after the break, scoring a fourth through Van Egmond's penalty.

Matildas coach Alen Stajcic said the scoreline -- cut when Yuka Momiki scored an injury time consolation -- didn't reflect Australia's dominance.

"It sounds funny to say when you score four but I thought we could have put the game to bed earlier," he told AAP. "We created 15 to 20 great chances against the World Cup finalists from two years ago. We were too powerful in the front third with our speed and power."

Stajcic hailed Kerr's inspired showing.

"She created havoc all day and maybe had opportunities to get another one or two," he said. "It's just reward for her. She's put in a lot of work over the last two or three years and had a lot of ups and downs."

The Matildas close out the friendly competition on Friday (AEST) against Brazil, who were beaten 4-3 in the later game.

A win over the South Americans will mean Australia win the tournament between the four top-10 ranked nations.