PULLMAN, Wash. -- UCLA and Washington State have battled on basketball courts for almost 80 years, but it would be difficult to describe their long-running series as a rivalry.
A true rivalry requires competitive games, and the Bruins have routinely routed the Cougars in a series that UCLA leads 102-15.
Alas, Washington State's 15th victory in the series may have been the most shocking of them all. The last-place Cougars knocked the 23rd-ranked Bruins out of first place in the Pac-12 Conference with a wire-to-wire, 73-61 triumph Wednesday evening at Beasley Coliseum.
"I take full responsibility," UCLA coach Ben Howland said. "Obviously, I didn't have our guys fearful of losing this game, because we didn't come out with the emotion and intensity that we needed to have."
Brock Motum led the Cougars with 20 points, and Royce Woolridge added 19. WSU (12-18, 3-14) had lost nine straight games, and eight in a row to UCLA.
"I'm proud of these guys (his teammates) for sticking with it," Motum said. "It could have been easy to give up a long time ago."
"I'm so happy for the guys," Washington State coach Ken Bone said. "I've said many times, they're a great group of kids. It's one of my most favorite teams I've ever coached."
The Bruins (22-8, 12-5 Pac-12), who were tied with idle Oregon for first place, were shockingly listless at the start of the game. UCLA entered leading the league in scoring and WSU was next to last, but the Cougars raced to leads of 7-0, 19-2 and 25-4 against a Bruins team riding a four-game win streak.
"Credit to them; they played awesome," said Jordan Adams, who led UCLA with 18 points.
"Obviously, a disappointing loss and effort," Howland said. "The way we came out defensively was poor."
The Cougars won with starting guards DaVonte Lacy and Mike Ladd sidelined with knee injuries. Ladd has missed six games and may be done for the year. Lacy tore a meniscus in Sunday's game at Washington and is scheduled to undergo season-ending knee surgery Friday.
"He's a huge part of our program," Bone said of Lacy. "He's one of the captains. One of our leaders."
Added Howland: "They lose Lacy and Ladd; you've got to give them a ton of credit. I thought Ken Bone did a great job of keeping his guys positive."
Motum, playing in front of family and friends visiting from his native Australia, tied his career high of 11 rebounds.
"Motum played great tonight," Howland said. "We really did a poor job defending him. He's a great player."
The Cougars outrebounded UCLA by a whopping 46-23 margin.
"Says a lot right there," Howland said.
The Bruins trailed 35-24 at the half. They pulled within six on a Shabazz Muhammad 3-pointer early in the second half, but the Cougars held tough and finished off the Bruins with three straight dunks before 4,268 spectators.
The first of those dunks, a vicious two-hander, was delivered by Will DiIorio. Bone again had praise for the hard-working junior, a former walk-on out of Bainbridge (Wash.) High.
"I think he has a lot of influence on other guys as far as, it (his effort) becomes contagious," Bone said. "All of a sudden, the guys are just scrappin'."
Added DiIorio: "It's been a while since we've got a win and we've been in every game, pretty much. To get a win like that is great, especially against a ranked team."
Muhammad had 14 points, but he went 4 for 19 from the floor. A finalist for national freshman of the year awards, Muhammad started the day ranked second in the Pac-12 with 18.3 points per game. Calfornia's Allen Crabbe was leading at 18.4.
The Bruins finish conference play Saturday at Washington. The Cougars' final league game is at home Saturday against USC. The Pac-12 tournament opens next Wednesday in Las Vegas.
NOTES: Howland called three timeouts in the first 10 minutes, 16 seconds to try to slow WSU's momentum. .. UCLA was ranked 32nd and Washington State 194th in ESPN's Daily RPI for the 347 NCAA Division I teams. Fresno State, at No. 148, represented the top team the Cougars had defeated. ... UCLA came into the game leading the Pac-12 in scoring (76.0) and field-goal shooting percentage (46.3). WSU was next to last in the two categories at 63.8 and 42.5, respectively. The Bruins were last in rebounding margin (minus-1.0 per game), but first in assists (17.2) and turnover margin (plus-2.7). Many of WSU's 17 turnovers came in the final minutes.