PORTLAND, Ore. - After a dominant performance in the semifinals of the Little League Softball World Series, Tucson's Sunnyside Little League 12-and-under team stands on the cusp of a first-ever championship for an Arizona team at the event.

For two innings, the Sunnyside offense was dormant, but a nine-run third inning led to a 10-0 win over Maunabo, Puerto Rico. The nationally televised game was called after four innings because of the 10-run "mercy" rule.

Sunnyside pitchers Jazmine Ayala and Yannira Acuña combined to throw four perfect innings. They struck out six Puerto Rico batters and didn't allow a ball to be hit out of the infield.

An undefeated team from McLean, Va., awaits Sunnyside. The Southeast Region representative defeated the East champions from Robbinsville, N.J., 6-3 in the other semifinal. The title game will be televised on ESPN2 at 8 tonight.

Chants of "A-RI-ZO-NA!" resonated throughout Portland's Alpenrose Stadium on Tuesday night, as the Sunnyside crowd showed itself to be the most raucous among the four teams competing in the semifinals.

Coach Rene Ayala won the Junior League baseball World Series as a player in 1992, and now his daughter Jazmine is one win away from joining him as a world champion.

"Back then we played Puerto Rico in the semifinal and Southeast in the final as well, so hopefully we have the same result this time," he said.

In the semifinal's decisive third inning, Sunnyside sent 12 batters to the plate, collecting five hits and three walks. Three crucial Puerto Rico errors allowed the runs to keep piling up.

"Some girls were nervous at first, but we really wanted to show everyone what we're made of in Tucson," Acuña said of playing in front of the ESPN2 cameras.

The outburst was a long time coming for Sunnyside, which had all four of its games in pool play decided by one run. A 2-1 loss to Canada was followed by wins of 1-0, 10-9 and 4-3.

"We were having some heart attacks during the first four games," Rene Ayala said. "We expected the games to be tough, so it's nice for our stress levels to have one that was easier to handle."

As in the West Region tournament in San Bernardino, Calif., Sunnyside lost its first game at the World Series. And just like at regionals, the Tucson girls rebounded to make it to the championship game.

Acuña said the key to victory in the final is "working together as a team, but also going out and having some fun."

Sunnyside is aiming to become the first world champion from Arizona. The last Arizona representative at the softball World Series was San Xavier Little League of Tucson in 2002. A West region team hasn't won since Glendale, Calif., took the title in 1990.