Prop Hope Rogers scored a double as the hosts ran in the final three tries after Australian winger Desiree Miller's try early in the second half made it a two-point game.
Australia's squad had bunkered in a hotel hallway earlier in the week during a tornado warning and will appreciate their return home to face New Zealand on the Sunshine Coast, on Anzac Day next Saturday.
The Wallaroos conceded nine first-half penalties and had only 30 per cent of the ball before the first break.
"We can definitely say that ill-discipline was the reason why we probably weren't able to play the rugby game that we wanted," captain Siokapesi Palu Sekona said post-match.
"Playing a host nation, they're always going to have an advantage in that space, but there's no excuse from our end.
"We've always been an us-versus-us mentality, and what it means is that we've got a lot of work to do once we go back.Â
"We'll travel home and start working towards that match."
Rogers opened the scoring and Maya Stewart was yellow-carded for Australia's repeat infringements.
But the Australians scored next, the captain crashing over after Samantha Wood's smart 50-22 kick.
Georgie Perris-Redding scored a deserved try for the US before halftime but, after Miller gave Australia hope, the hosts shut the door in an emphatic final 25 minutes.
