The Levittown (L.I.) Slammers won two games yesterday to advance into the semifinals of the girls’ softball 16-and-under Babe Ruth World Series yesterday in Lamar, Colo.

The Slammers, who had finished pool play with a 3-1 record, yesterday beat North Olympic (Wash.) 6-3 behind Ashley Massoni. She pitched all seven innings and struck out seven.

The nightcap resulted in a 2-1 victory over Wausau (Wisc.), sending the Slammers into a semifinals showdown today against Wilson County (N.C.).