Kalen Pimentel struck out nine to help Vista, California to a 6-2 victory over Maitland, Florida in the first of two United States semifinal games at the Little League World Series. The California team advanced to the U.S. championship game on Saturday and will face the winner of Thursday's semifinal between Ewa Beach, Hawaii and Lafayette, Louisiana. Pimentel made headlines earlier in the tournament with an 18-strikeout performance, but on Wednesday still earned the win despite allowing two runs on six hits with two walks. Dante Bichette Jr., son of the former major league slugger, took the loss for Florida. He gave up six runs -- four earned -- on seven hits in 5 1/3 innings. The game was tied at 2-2 until the fourth, but Reed Reznicek led off for California with a walk, advanced to second on a bunt and scored when Florida centerfielder Lee Dunnam overran a single by Daniel Gibney. The Florida squad couldn't muster another run against Pimentel and California tacked on three runs in the sixth to open up some breathing room. Bichette, in addition to his effort on the mound, had two hits and finished 8- for-11 in four games. In an International semifinal earlier on Wednesday, Japan rolled to an 11-0 victory over Canada. Yusuke Taira and Kisho Watanabe each had three hits with a home run for the team from Chiba City, which will face the winner of Thursday's other semifinal between Guam and Curacao in Saturday's International title game. Taira also doubled and tripled while driving in four runs in the victory. The Japanese team has outscored its opponents 30-4 in winning its first four games of the tournament. Takuya Sakamoto struck out six and surrendered just one hit in four innings to earn the win. Nathan de la Feraude had the lone hit for the team from Surrey, British Columbia. The score was 3-0 until Japan erupted for eight runs in the fifth and the game was stopped by the mercy rule after Canada failed to score in the bottom of the inning.