The Austalian women's water polo team have lost a tense semi-final against Olympic champions USA at the FINA World Championships in Russia.

The Aussies' 8-6 loss in Kazan on Wednesday means they will now battle it out for the bronze medal.

Australia showed promise for the first half of the match, but a few costly lapses in defence allowed the Americans to score the first three goals of the second half, putting the game out of reach.

The Australians will hit the pool against either Italy or the Netherlands, who were yet to contest the other semi final, on Friday night at 8:30pm local time (3:30am Saturday AEST).

Australian star Ash Southern, who starred for the side in both attack and defence, said the team was devastated, having failed to win the individual player tussles.

"We're obviously gutted," Southern said.

"We go into these games trying to build each game and in this one we came out strong but I think we just let ourselves down one on one.

"We lost our one on one battles in defence. Our attack wasn't great but in the end it came down to defence.

"We go onto the next game and hopefully we can win the bronze medal," she said.

The Stingers had put in a stellar performance that their coach Greg McFadden labelled 'the best in years' against another of the tournament's semi-finalists, the Netherlands, in their final group stage game last week but then almost fell to China in Monday's quarter-final.

AAP