Sweden goalkeeper Zecira Musovic says she is "in the zone" at the Women's World Cup after a succession of crucial saves denied the United States in an ominous sign for quarterfinal opponents Japan.

The Chelsea stopper exploded on the global stage with her breathtaking performance in their penalty shootout win against the defending champions in Melbourne on Sunday.

The 27-year-old produced 11 saves, many world-class, to keep the Americans at bay over 120 minutes of action.

"You can only love the feeling of when you're in the zone and stuff is happening in a way that you're just doing it," said Musovic, who battles with Germany's Ann-Katrin Berger for a starting place at Chelsea.

"I had a really good feeling before the game. We had a good feeling in the squad, we know what we are capable of."

Sweden coach Peter Gerhardsson said her player-of-the-match antics could have weighed on American minds when they lined up to take their penalties.

Megan Rapinoe, Sophia Smith and Kelley O'Hara all missed from the spot, leaving Lisa Hurtig to send Sweden through 5-4 and become the first team ever to eliminate USA before the semifinals.

"I don't know what she did, what mental thing that she did to make them put them over the bar and things like that," he said.

"But I think goalkeepers like these kinds of penalties, they're mentally prepared, that's their game.

"She was good in the game. Even if she didn't save any penalties, I think for the other team, maybe they put it outside because they know that if it's not a good penalty, maybe she takes it."

Gerhardsson will be banking on Musovic once again when the world No 3 meet in-form Japan in Auckland on Friday, with a semifinal berth at stake.

He is expecting a different tactical game from the 2011 champions who powered into the quarterfinals with a 3-1 win over Norway.

"We met Japan in the (Tokyo) Olympics, and they are very skilful in their technique," he said, referring to a game Sweden won 3-1.

"They don't play as directly as the US so it's going to be a different kind of game.

"It'll be more about possession. They play a bit more like Italy, skilful and taking moves forward with many passes.

"So for us it's going to be about good defending, maybe a bit lower, and then transition is going to be important."