RIO DE JANEIRO -- The United States again got off to a slow start in women's field hockey but regained its composure and knocked off a world power for its second straight win against a top-three team.

On Monday, the United States defeated No. 3 Australia 2-1 as Michelle Vittese and Caitlin van Sickle scored for the Americans. The U.S. team defeated No. 2 Argentina 2-1 in its Olympic opener on Saturday.

The Americans said their ability to bounce back has been consistent.

"I think that's just kind of our DNA," van Sickle said. "We don't have the greatest start. We're always going to keep coming and keep coming after you."

United States goalie Jackie Briggs had six saves and allowed just one goal on 15 shots. Australia couldn't convert any of its four penalty corners against her. The crowd chanted: "Jackie! Jackie!" after the match.

The fifth-ranked Americans, who lead Pool B with six points, moved closer to qualifying for the quarterfinals. The top four teams in each six-team pool advance. The United States has the maximum point total two games into pool play and already has played the two highest-ranked teams. The Americans said that won't affect their focus as they prepare to play Japan on Wednesday.

The U.S. women's field goal team has produced back-to-back upsets of world powers, beating No. 3 Australia 2-1 on Monday. AP Photo/Dario Lopez-Mills

"We literally focus on just one game at a time," van Sickle said. "We don't necessarily look at the draw. You've got to play every team in your pool, so it doesn't really matter."

The Americans haven't medaled since 1984, and Argentina and Australia have been good for years, while the United States is an emerging program. But the United States beat Australia for third place at the Champions Trophy event in June, fueling the team's confidence heading into the Rio de Janeiro Games.

"It's not the underdog, it's not whatever, it's just us, united as strong and resilient and gritty," Vittese said.

The Americans dealt a major blow to Australia. The Hockeyroos dropped their opener to Britain 2-1 on Saturday and now have zero points with three pool play matches remaining. They play India next.

"It's managing the distractions in the [Olympic] Village, managing the distractions of the other results going on in the competition," Australia's Georgie Parker said. "We're going to be scouting really hard against India, preparing as well as we can, making sure we do that right recovery and everything will go smoothly from there, we hope."

This one was especially rough for Australia because it was hit with two yellow cards and a green card in the third period alone, forcing the Hockeyroos to play shorthanded.

"We are a really physical side, and we're very aggressive in going for the ball, so sometimes you do have some casualties along the way," Parker said. "I guess it's about managing to get the right balance of being aggressive at the ball with playing within the rules."

The United States spent the early part of the match defending its goal as the aggressive Australian attack put the Americans on their heels. Briggs stopped four shots in the first period, and the match remained scoreless.

Vittese scored on a penalty corner to put the United States up 1-0 in the second period. The Americans went up 2-0 in the third period when van Sickle scored on a penalty corner. There was a video referral because the pass near the goal was high, but it was not considered and the goal was upheld.

Australia came back less than two minutes later with a goal by Kathryn Slattery.

The Hockeyroos got another penalty corner with two minutes remaining in the fourth period, but Briggs deflected a shot high.

"We just took it moment by moment," Briggs said, "tried to stay in the moment and not think about, `Oh, there's only so much time left and the score.'"