UCSB redshirt freshman Tallulah Froley had a team-high 16 kills as the Gauchos beat Cal Poly in four sets to pull into a tie for first place with the Mustangs in the Big West Conference.
It is just the second loss for Cal Poly in their last 33 league matches.
The Gauchos won by the scores 25-19, 25-21, 15-25, 25-21.
UCSB is now 16-2 overall for the season and 6-1 in the Big West.
Cal Poly is 13-6 overall and 6-1 in Big West play.