New coach Tony Gustavsson kicked off his tenure with five tough friendlies against Germany, the Netherlands, Denmark, Sweden and Japan when the Matildas conceded 14 goals, lost four of five games and won none.

But a dominant showing at Tokyo Stadium on Wednesday night, bar a stunning goalkeeping performance from New Zealand's Erin Nayler and the Kiwis' injury-time consolation goal, kicked off Australia's Olympics campaign with their first victory under Gustavsson.

Central to that was Kerr, who assisted Tameka Yallop's opener and snapped a five-game drought when scoring a goal herself in a stellar captain's performance.

"It's always good to win your first game - I think it gives you a lot of confidence going in to the rest of the tournament," Kerr told the Seven Network.

"Everything was for this moment so we feel as prepared as ever.

"The results before didn't go our way but it was all for this game and look, we've got the three points and we'll move on."

The 2-1 scoreline belied a dominant performance from Australia, who seized control of the clash in a scintillating first half.

Gustavsson reverted to a back four with full-backs Ellie Carpenter and Steph Catley creating chances at will and in the 20th minute the Matildas capitalised on their dominance through some delightful one-touch football.

Yallop pounced on a turnover, worked the ball to Kyah Simon and burst forward.

Simon cleverly headed the ball on to Kerr who flicked it to Yallop, with the midfielder taking a touch then smashing the ball into the roof of the net.

In the 33rd minute, Catley whipped a corner into the near post where Kerr smacked a thumping header home off the crossbar to make it 2-0.

Simon spurned a golden opportunity to add a third when she hit a chance straight at Nayler in the 47th minute and Kerr put a backheel just wide three minutes later.

It proved the tale of the second half as the Matildas had plenty of chances but failed to extend their lead, largely due to several sharp Nayler saves.

Teenagers Mary Fowler and Kyra Cooney-Cross made their Olympics debuts in the 75th minute but neither were able to find a goal.

In the first minute of injury time, the Football Ferns snatched a consolation goal on the counter.

Ria Percival headed a cross back across goal for substitute Gabi Rennie, who nodded home just two minutes into her international debut, forcing the Matildas to scramble to lock up all three points.

Australia next face Sweden, who are coming off a scintillating 3-0 win over world champions the United States, on Saturday in a stern test in their bid to progress from group G.

Australia drew 0-0 with the Swedes in last month's friendly.

Australian Associated Press