All the joy of a 2-0 win over Turkiye last weekend was rubbed out quickly when Socceroos defender Cameron Burgess but through his own net in the 11th minute, and the USA didn't let up from that moment.

Two minutes before half-time, more sleepy defending saw a rebounded shot put away by Alex Freeman, who was initially flagged for offside but was cleared after a video assistant referee (VAR) check, allowing the goal to stand and leaving Australia searching for answers at the break.

Australia coach Tony Popovic dropped both goalscorers against Turkiye, Nestory Irankunda and Connor Metcalfe, from the Socceroos' starting XI, but was forced to bring them on after half-time to try to turn the tide.

But they rarely looked like getting back into the match in a second half which became increasingly fractious and lacked quality.

"I don't know if it was the occasion, but we looked sluggish, heavy-legged," Popovic said.

"I think the players showed how good they are in the second half, but obviously at this level you can't give away that much in the first.

"But if we want to win the competition, we need the whole team. And all the players need to be important."

The USA started slightly nervously in front of a full house but quickly settled into the match, with Weston McKennie particularly influential, and the lead was well deserved.

Folarin Balogun tore down the left flank and played the ball towards Ricardo Pepi, replacing the injured Christian Pulisic, and the covering Burgess sent the ball into his own net.

The Socceroos struggled to get out of their own half as the tournament co-host maintained control, with Australia's best moment of the first half coming just before the hydration break, when Freeman blocked Mathew Leckie's threatening cross.

The USA finally got the second goal its dominance deserved in the 43rd minute. A free-kick was played to Sergino Dest on the edge of the area and his shot was blocked, but looped into the air with Socceroos goalkeeper Patrick Beach on the floor to allow Freeman the simplest of headers.

The second half lacked quality and chances for either side, with United States content to protect its lead and conserve energy, but Australia's Harry Souttar missed a golden opportunity with five minutes to play which could have set up a tense finale.

The final whistle sparked jubilant celebrations on a sun-splashed afternoon in Seattle, and sees the USA on to six points and into the Round of 32.

"It was surreal ... obviously at first it was disallowed so I was kind of anxious when it went to VAR," Freeman said of his goal.

"It was so emotional for me because you dream of this moment."

Mauricio Pochettino's side will conclude Group D against Turkiye next Friday (AEST) at Los Angeles Stadium, while Australia, on three points, faces Paraguay at San Francisco Bay Area Stadium.