OKLAHOMA CITY — Alissa Haber and Andrea Duran homered as the U.S. exacted a measure of revenge for its loss in the Olympic gold medal game, defeating Japan 6-1 tonight at the World Cup of Softball.

Haber smashed the first pitch thrown by reliever Naho Emoto (0-2) the opposite way over the left-field wall to put the U.S. ahead 2-1 in the bottom of the fifth inning. As lightning from an approaching storm could be seen in the distance, Duran added a two-run blast later in the inning to extend the lead.

The stakes weren't nearly as high in the rematch, and many of the faces were different, too.

If anything, the game was a chance for the next generation of American softball stars to make their mark in the rivalry.

Still, there was plenty of emotion. Cat Osterman (1-0), who lost the gold medal game, pumped her left fist after striking out Rei Nishiyama to end the game. It was the 13th strikeout in a four-hitter for Osterman.

Japan (1-2) used four pitchers. Starter Mika Someya and Makiko Fujiwara combined to strand four U.S. runners in scoring position in the first three innings before the Americans finally broke through in the fourth.

Pinch-runner Chelsea Bramlett raced in to score the game's first run on Ashley Charters' chopper just in front of home plate, diving in head first to beat the tag of catcher Maki Tanigawa.

But the Japanese rallied right back to tie it in the fifth on Rei Nishiyama's sacrifice fly.

That set the stage for Haber, one of 10 rookies on the U.S. roster. She came through with her third extra-base hit in 15 games with the U.S. team. She later added an RBI single and scored on Jenae Leles' grounder.

After Duran's homer, the teams were taken off the field for a 53-minute weather delay, and the capacity crowd of 6,196 was asked to leave the seating area to avoid the risk of lightning.

U.S. 15, CANADA 0, 4 INNINGS

Natasha Watley hit a grand slam, and Duran and Leles also homered as the U.S. piled up its most lopsided victory against its northern rival.

The Americans jumped on starter Leah MacIntosh (0-1) for five runs in the first and added nine more in the third — all 14 runs coming with two outs. The game ended because of the mercy rule following Ashley Hansen's RBI single in the bottom of the fourth.

The Americans eclipsed their 14-1 victory at the 1991 Pan-American Games for the largest margin in the series.

After back-to-back RBI singles by Jennie Finch and Leles, Duran broke the game open by smacking a three-run homer the left-center field fence.

Reliever Marissa Litster then got herself into trouble by walking three straight U.S. batters before Watley lined a 2-2 pitch over the fence in right to make it 9-0. The Americans tacked on five unearned runs after third baseman Megan Timpf couldn't handle Kaitlin Cochran's two-out grounder, capped by Leles' third three-run blast in three games.

Monica Abbott (1-0) struck out seven and allowed two singles.

CANADA 6, ITALY 4

Jennifer Yee homered and Jennifer Caira threw six strong innings in relief as Canada overcame a three-run deficit.

Italy had a 3-0 lead in the first inning when the game was suspended Thursday night due to an approaching storm, but the Canadians took control after play resumed Saturday morning.

Sheena Lawrick tied it with an RBI triple in the bottom of the third and scored on Evelyne Pare's single to make it 4-3.

Yee added a solo shot in the fourth inning. Caira (2-0) allowed two hits and one unearned run.

Kate Gentile hit a three-run homer for Italy (0-4), which is playing in its first World Cup.