PULLMAN, Wash. -- Cal had a prime opportunity to separate itself from the rest of the Pac-12 Conference, but it was Washington State freshman DaVonte Lacy who got ample separation.
Lacy found himself open on the left wing and knocked down a go-ahead 3-pointer while being fouled, boosting the Cougars to a 77-75 win at Beasley Coliseum on Saturday.
The Bears (16-5, 6-2), who saw their four-game win streak halted, had a chance to regain the lead in the waning moments, but Jorge Gutierrez's 3-point attempt was off the mark as the horn sounded.
The loss, combined with Oregon's win over UCLA, dropped Cal into a first-place tie with the Ducks, who lost to the Bears earlier this month.
Gutierrez led five players in double figures with 19 while Justin Cobbs (15), Allen Crabbe (14), Harper Kamp (12) and David Kravish (11) had a hand in the Bears' erratic offensive output.
Cal coach Mike Montgomery wasn't too content with his club's effort on the other end of the floor.
"Defensively we weren't very good," Montgomery said. "(Washington State guard Faisal) Aden obviously is confident right now, but of the nine shots he (made), seven were layups. That was disappointing. No excuse for that.
"We got a little stagnant there on offense. We had our chances. Nobody to blame but ourselves."
Aden, who scorched Stanford with a career-high 33 points Thursday, scored 16 of his 24 points against the Bears in the first half.
The Bears turned eight of the Cougars' turnovers into 15 points, which was perhaps their biggest boon in a 40-34 halftime edge.
The second of Crabbe's four 3s gave Cal its biggest lead of the game -- a 32-21 edge -- at the 6:48 mark.
WSU (11-8, 3-4) adjusted its scheme in the second half, putting a much smaller lineup on the floor.
Initially, it disconcerted the Bears, who succumbed to a 13-4 run that gave the Cougars their first lead when Abe Lodwick hit a 3 to make it a 47-44 game.
"They just kept at it. Not that we gave up," Kamp said. "They just played with a lot of confidence, and we weren't able to shut that down."
Lodwick, a reserve guard, saw most of his minutes in the second half when the Cougars sat starting center Charlie Enquist. All four of Lodwick's 3-pointers were in the latter period.
"They went to a smaller lineup, caused us problems," Montgomery said. "We couldn't get much help out of our bigs because they were spread all over the floor."
The lead was short-lived, though, when Cobbs and Gutierrez came up with a back-to-bank transition jams via steals. From there, six lead changes and seven ties ensued.
With the score knotted at 74, Gutierrez's 3 was off the mark, and Washington State regained with possession with 33 seconds remaining. It was after the timeout in where Lacy, who finished with 14 points, connected on the game-winner with 18 seconds remaining with a chance at a four-point play.
Cal was able to get Cobbs on the line with six second left. He connected on the first, intentionally missed the second, and Cal grabbed the rebound to set up Gutierez's potential game-winner.
"We were really hoping to get a leg up on the rest of he conference," Kamp said. "But we didn't play with that sense of urgency."
The Bears, who take on Stanford on Saturday, saw their bench outscored 42-4.