AP

Washington State's Derrick Low, left, takes a shot as Washington's Venoy Overton defends during first half basketball action at the Hec Edmondson Pavilion in Seattle, on Saturday, Jan. 5, 2008.

SEATTLE - The last time No. 4 Washington State started a season 13-0, its schedule included the likes of Puget Sound, Whitman and Deserts Independent.

That was the 1935-36 season.

And while critics may lament that the schedule leading to the Cougars' 13-0 start this season hasn't been much tougher than it was 72 years ago, Washington State remains only one of six unbeaten teams in the country after Saturday night's 56-52 win over Washington to open Pac-10 Conference play.

The Cougars now own wins on the home floors of their two biggest rivals -- Washington and Gonzaga -- and road wins at Boise State (11-3) and Baylor (11-2). While the rest of their non-conference schedule was pedestrian at best, the Cougars have four impressive road wins and know their biggest challenges await in conference play.

This week's test: The Cougars play at USC on Thursday night, then face No. 5 UCLA on Saturday.

The slugfest against Washington might have been the perfect primer for what awaits the Cougars the next two months.

"That's how the Pac-10 is going to be," Washington State guard Derrick Low said. "Teams are physical. Teams are going to beat you up. It's not going to be easy, and I think that's how every game is going to be."

Saturday night's brawl, with bodies flying all over the floor and every possession of the utmost importance, gave Washington State its first six-game win streak over the Huskies since 1941-42.

Washington (9-5) showed resolve with its willingness to play the Cougars' prodding, defensive-oriented style. But when it mattered most in the final minutes, Washington State showed just how it's done.

Washington State held the Huskies to just one field goal in the final 6:20. Washington missed 10 of its final 11 shots, and didn't help itself by missing four free throws in the final 4 1/2 minutes.

With its defense flustering the Huskies, Washington State's offense executed perfectly, scored 11 of the final 15 points, highlighted by an 8-0 run that started with Aron Baynes' dunking three-point play that pulled the Cougars even at 48-all. Baynes finished with a game-high 16 points.

Low then added a deep 3-pointer and the Cougars never trailed again.

"These guys have played a few Pac-10 games and I think that experience helped," Washington State coach Tony Bennett said.

Should the Cougars be able to handle USC on Thursday night, then Saturday's showdown at UCLA will give an early boost to the winner in the conference title race.

Just don't expect a lot of points to be scored. The Bruins are allowing just 54.9 points per game. The Cougars are even better, at 49.8. UCLA has also won six straight over the Cougars, but four of those have been decided by three points or less.

Saturday night's brawl against Washington was likely just the start for the Cougars.

"We need to play our defense every game," Baynes said. "If we don't, we can get beaten by every team we play. But if we do, we can beat every team that we play."