Emily Myers scored seven points in the overtime period as the Timberwolves edged the visiting Tigers.
The Battle Ground loss means Skyview has clinched the Class 4A Greater St. Helens League title.
Myers and Nesija Selava each scored 17 points for Heritage. Selava made five 3-pointers, including one with about 10 seconds left in the fourth quarter to tie the score.
Battle Ground failed to score on the final possession in regulation.
Heritage (11-7) improved to 5-5 in league play, and second-place Battle Ground (10-8) is 6-4.Haley Grossman led Battle Ground with 15 points. Chelsie Aguigui hit two 3-pointers in overtime for the Tigers.