After four ties and six lead changes in the final 10 minutes, Brownridge gave the Broncos (8-15, 4-7 West Coast Conference) the lead for good at 79-77 with 2:07 left. He stretched the lead to four at 1:30 with another driving layup and nailed a catch-and-shoot 3 from the top of the key to make it 84-79 with 46 seconds left.
Alec Wintering twice closed the Portland deficit back to two but turned it over with 15 seconds left when the Pilots (9-15, 3-8) trailed by four.
KJ Feagin, who finished with 15 points, made all six free throws in the final 32 seconds to secure the win. Matt Hubbard scored 10.
Wintering had 31 points and Bryce Pressley scored 17 for Portland.