In his first year as head coach, Jay Miller has the U.S. softball team once again dominating the competition.

OKLAHOMA CITY — In his first year as head coach, Jay Miller has the U.S. softball team once again dominating the competition.

Lauren Lappin homered to start a three-run rally in the third inning, and the United States beat Australia 3-1 Monday night in the World Cup of Softball championship game.

Coming off a loss in the gold medal game of last year's Olympics, the Americans have won their first 20 games this year with a roster featuring 10 rookies — enough to outnumber the veterans.

The U.S. (6-0) outscored opponents 51-4 and, fittingly, got its toughest test in the finals.

"Every time we take the field, we don't just want to win. We want to dominate," said two-time Olympian Cat Osterman, who got the save with 1 2-3 scoreless innings. "We want to set a standard. The rookies are jumping right in the boat and going with us on that one."

Alissa Haber and Andrea Duran followed Lappin's homer with RBI singles to push the lead to 3-0, and Monica Abbott and Osterman combined to make it stand up for the Americans' third straight World Cup title.

Stacey Porter homered for Australia, the bronze medalist at the 2008 Beijing Olympics.

"This team can get a lot better. That's what's sort of scary and exciting at the same time, to see the potential that we have," said Miller, who took over for Mike Candrea, who stepped down after the Olympics. "Now it's our job to get them there."

It was perhaps a sign of the times that Abbott, the former Tennessee lefty who gave up just one earned run in 24 innings at the Olympics last summer, got the start in the championship game instead of Osterman or fellow veteran Jennie Finch.

Finch had thrown five scoreless innings against Australia the day before and Osterman, who no-hit the Aussies in Beijing, last pitched on Saturday night against Japan.

But this is a new American team, after seven players who'd played in at least two Olympics retired. So far, the youngsters are 20-0 with titles at the Canada Cup and the World Cup.

"We have a really young team, and this is the first summer that a lot of them have been in this type of situation," Osterman said. "For us to come through and bring home two gold medals in the two tournaments we've played so far is great."

It took some help from the few remaining veterans to get past Australia (3-3), which beat 2008 Olympic gold medalist Japan on its way to its first championship game at the World Cup.

Lappin, an Olympian last summer and an alternate in 2004, got the Americans on the board with her first home run in 16 games this year. Her drive off Justine Smethurst just cleared the right-field fence.

Lappin hit .182 at the Canada Cup before finding her stroke again in Oklahoma City, which will also host the world championships next July.

"She had been struggling a little bit offensively ... and to see her step up like that on this stage tonight I think is a big boost for her and a big boost for our ballclub," Miller said.

Then Osterman, who played on each of the last two Olympic teams, came in to close the door when Abbott ran into trouble. She entered with runners on first and second and struck out Danielle Stewart and Jodie Bowering to end the sixth inning.

With the tying run on first base, Osterman got Kylie Cronk to line out to right field to end the game.

"You saw a lot of character and a lot of heart and a lot of fight," Miller said. "You need games like this to sort of see what you're made of, to see where we're at."

Canada 4, Japan 1

College softball player of the year Danielle Lawrie finished a shaky World Cup with a four-hitter as Canada claimed third place.

Jennifer Yee set a World Cup record with her fourth home run as the Canadians (4-2) jumped out to a 3-0 lead after three innings.

Haruna Sakamoto, who hit a grand slam off Lawrie a day earlier to knock Canada out of contention for the championship game, had an RBI single in the fourth for Japan (3-3).

Netherlands 8, Italy 1, 6 innings

Nathalie Timmermans drove in three runs and four other Dutch players homered as the Netherlands won the fifth-place game.

Natalie Gosewehr opened the bottom of the first with a leadoff homer, and Virginie Anneveld and Chandal Versluis added home runs in a five-run fifth inning for the Netherlands (2-4).

The mercy rule was invoked when Saskia Kosterink hit a solo shot with two outs in the sixth.

Italy (0-6) scored its only run on a throwing error by Rebecca Soumeru.