The Australian women's water polo team, the Aussie Stingers, have begun their three match test series against the USA with a disappointing 13-12 loss at Sydney Olympic Park Aquatic Centre on Tuesday night.

After securing a convincing 7-4 victory in Saturday's Water Polo Pan Pacs gold medal match in Melbourne, the Stingers failed to show the same intensity that saw them record six straight wins to start the year.

Both teams showed early signs of lethargy with neither outfit able to break the 0-0 deadlock.

Stingers driver Jane Moran opened the scoring for Australia in the third minute of the match, before triple Olympian and USA captain Brenda Villa levelled the game.

The stalemate continued for remainder of the half with the two teams unable to penetrate the opposition defence.

The scores were locked at 5-5 at the main break with captain Kate Gynther scoring late in the piece, before America went on a 6-3 run in the third term to open a three goal margin.

The Stingers made a come back in the last quarter to reduce the margin to one, with Rowie Webster scoring her fourth and Gynther her third, but America was strong enough to hold on for the win.

Australian head coach Greg McFadden was frustrated at the lack of energy and was concerned at the number of goals the girls let in.

"Our intensity wasn't there and our defence was very ordinary today," an honest McFadden said.

"To go from allowing America only four goals in the Pan Pacs final to 13 today was very disappointing.

"Maybe the girls thought it would be too easy, but you can never treat the American's lightly and we've paid the penalty tonight.

"We have to go back and look at how we have performed as a whole and turn it all around for the next game."

The loss is a minor setback in the Stingers' Olympic campaign as they look to become the first women's water polo team to win two gold medals at the Olympics.

The Stingers' next match against the USA is at the Sutherland Leisure Centre on Thursday at 7.00pm.

Result: USA 13 bt Aussie Stingers 12

Quarters: (3-3, 2-2, 6-3, 3-4)

AUS Scorers: Rowie Webster 4, Kate Gynther 3, Nicola Zagame 2, Jane Moran, Ashleigh Southern, Holly Lincoln Smith

USA Scorers: Brenda Villa 3, Kami Craig 2, Maggie Steffens 2, Elsie Windes, Lauren Wenger, Jessica Steffens, Tanya Gandy, Juliet Moss, Melissa Seidemann

Australia: Alicia McCormack, Gemma Beadsworth, Sophie Smith, Holly Lincoln-Smith, Jane Moran, Bronwen Knox, Rowie Webster, Kate Gynther, Glencora Ralph, Ashleigh Southern, Melissa Rippon, Nicola Zagame, Lea Barta

USA: Betsy Armstrong, Heather Petri, Melissa Seidemann, Brenda Villa, Lauren Wenger, Maggie Steffens, Courtney Mathewson, Jessica Steffens, Elsie Windes, Kelly Rulon, Annika Dries, Kami Craig, Tanya Gandy, Tumua Anae, Sami Hill, Lauren Silver, Juliet Moss