After falling to Southern California Thursday, the Cougars dropped into the conference cellar, but the Trojans fell to Washington Saturday, allowing WSU (10-20, 3-15 Pac-12) to climb one notch.
Ike Iroegbu had 14 points and D.J. Shelton scored 10 points and grabbed 14 rebounds as WSU snapped its eight-game losing streak.
UCLA jumped out to a 9-0 lead, but then the Bruins then went cold from the field.
Washington State went on an 8-0 run of its own to take its first lead, 26-24, on an Iroegbu 3-pointer with 3:36 left in the half. The Cougars finished the half on a 16-2 run to lead 34-26.
Kyle Anderson scored 19 points and Bryce Alford had 10 for UCLA (23-8, 12-6).