Griffin Andreychuk (Nanaimo, B.C., Canada) scored on an error before Jeffrey Morgan (Auburn, Wash.) and Lucas Denney (Goldendale, Wash.) batted in three more runs to give SU a 4-0 lead after the first half inning.
UVU took one run back in the bottom of the first but the Redhawks tacked on two more in the third to lead, 6-1.
The Wolverines cut their deficit in half, 6-3, after four innings and Utah Valley would tack on 10 runs between the sixth and seventh innings on a combined 10 hits.
Max Modeste (Roseville, Calif.) hit a two-run bomb in the bottom of the ninth to pull the Redhawks within five, 13-8, but it would be as close as they would come.
Seattle U now will play No. 2 NM State on Saturday, May 28 at 3 p.m. in an elimination game, with the winner advancing to game one of the championship series on Saturday night at 7 p.m. vs. Utah Valley.
Stay tuned to @SU_Baseball on Twitter and WACSports.com for all the latest updates throughout Saturday.