BEIJING — Cat Osterman pitched a no-hitter, Crystl Bustos hit a two-run homer and the U.S. softball team extended its Olympic winning streak to 16 games with a 3-0 win over Australia on Wednesday.

Osterman was locked in a pitcher's duel for four innings with Tanya Harding, who had handed the U.S. team two of its four losses in the games since 1996. Osterman struck out 13 and walked just two as the Americans, seeking a fourth straight gold medal, posted their 14th shutout during the winning streak in a rematch of the gold-medal game from 2004 in Athens.

"It's good to get a game like this under our belts," Osterman said. "It's good to have your backs against the wall every now and then. It shows how we keep fighting. We're not just going to let down because another team is competing with us."

Natasha Watley hit an RBI single off Harding to snap a 0-0 tie in the fifth, and Bustos, the most feared hitter in softball, connected for her 10th career Olympic homer in the sixth.

Earlier, China improved to 2-0 with a 7-1 win over Venezuela.

In the evening session, Japan faces Taiwan and Canada plays the Netherlands.

One day after scoring an Olympic record 11 runs in a tournament-opening rout of Venezuela, the Americans were blanked for four innings before finally pushing a run across against Harding in the fifth.

Lovieanne Jung walked with one out, and one out later, the U.S. team's second baseman stole second. Up came Watley against Harding.

Watley battled to a full count before slapping a single to left-center, scoring Jung without a throw.

The Americans made it 3-0 in the sixth when Bustos, the ponytailed powerhouse, hit her second homer in China.

Jessica Mendoza walked leading off and Bustos, who normally pulls her homers deep over the fences in left, dropped one over the right-field wall, giving the U.S. and Osterman a cushion for the seventh.

"She's a beast when it comes to hitting," Osterman said of Bustos. "You can throw her outside and she can beat you. You can throw it inside and she can beat you. You can throw it in the dirt and she can golf it. You can throw it 10 feet over her head and she can tomahawk it.

"We all kind of laugh because she can do almost anything that she wants."

Osterman then struck out the side in the final inning.

The 36-year-old Harding, known simply as "Tee" to her teammates, handed the U.S. its last loss in the Olympics, beating them in a 13-inning marathon on Sept. 21, 2000 in Sydney. Harding struck out 18 that day in going the distance and out-dueling Lisa Fernandez, who fanned 25.

Harding also defeated the U.S. in 1996 at Atlanta, the Americans' lone loss en route to winning its first gold in softball's debut.

For a while, it looked like Harding would bedevil the U.S. again. But the world's best lineup came up with the big steal, clutch hit and another Bustos blast.

Don't they always?

"It," said Bustos, "was just a matter of time."

It was Australia's second straight loss after the defending silver medalists dropped a 4-3 decision to Japan in its tourney opener.

Osterman worked her way out of a situation as sticky as the heavy air in Fengtai Softball Field in the third.

She walked Danielle Stewart leading off and Belinda Wright sacrificed. With a 3-2 count, Osterman was called for taking longer than 20 seconds between pitches by Canadian plate Nancy Morrison, who monitors a clock on the center-field wall. The infraction is an automatic ball and Morrow was awarded first base.

Osterman, though, struck out Kelly Wyborn and Stacey Porter, punctuating the last one with a scream and fist pump as she headed to the dugout.

In other round-robin play, China improved to 2-0 with a 7-1 win over Venezuela, and Japan won its second straight by beating Taiwan 2-1. Canada plays the Netherlands in Wednesday's final game.

On Thursday, the U.S. will face the Canadians, who nearly beat the Americans in June.