Toryi Midland scored 18 points, Lauren Weatherspoon added 13 and the Titans pulled away for a 4A Greater St. Helens League win at home.
Brianna Adams scored 16 points for Battle Ground (6-11, 0-5), which trailed 36-27 at halftime.
“Battle Ground came out and played really well in the first half,” Union coach Gary Mills said. “After halftime, we had to redouble our efforts.”
Union (14-4, 5-1) pulled away by outscoring the Tigers 17-5 in the third quarter.
UNION 61, BATTLE GROUND 39