The Titans used pressure defense to jump on Marshfield of Coos Bay, Ore., from the opening quarter en route to the win at the West Albany Tournament.
Union (4-1) held Marshfield to 10 points in the first half, and led 34-10.
Kendra Preuninger topped Union in scoring with 14 points, and Tuileisu Anderson had 10.
Union will face West Albany on Saturday.
UNION 56, MARSHFIELD 25
MARSHFIELD — Stall 4, Chavez 6, Scott 2, Bab 6, Mosieur 2, Garrett 1, Mayer 4. Totals 10 (1) 4-8 25.
UNION (4-1) — Grace Davis 6, Tessa Vanderpool 7, Tuileisu Anderson 10, Kendra Preuninger 14, Molly Petrie 0, Katie Burbank 2, Hannah O’Donnell 6, Katherine Williams 0, Jessica Chatman 8, Emily Rowe 3. Totals 22 (6) 6-10 56.
Marshfield 5 5 11 4–25
Union 26 8 14 8–56