PULLMAN, Wash. (AP)—It was an astonishing sight.

There was 6-foot-10, 270-pound center Aron Baynes stealing the ball and racing the length of the court for a dunk that gave Washington State a five-point lead.

"I was lucky enough to finish it, emphasis on lucky," Baynes joked shortly after No. 17 Washington State beat Arizona State 59-47 on Thursday night to hold on to third place in the Pac-10.

Baynes’ play gave the Cougars a 45-40 lead, and more importantly, electrified the crowd and his teammates.

"I was just hoping that he didn’t fall down or lose the ball," said Washington State guard Derrick Low, who finished with 15 points. "I just never saw him do that before."

That’s not completely true. Guard Taylor Rochestie said Baynes recently had a steal in practice.

"Somebody said, `Baynes, be realistic, practice what you are going to see in games,"’ Rochestie said with a laugh. "I guess we’ve just got to let Baynes go."

Baynes admitted to being surprised by the breakaway, which began when he intercepted a pass intended for Arizona State’s Jeff Pendergraph.

Baynes and Rochestie both had 10 points and six rebounds for surging Washington State (21-5, 9-5) which won its fourth straight, the longest current winning streak in the conference.

But it was defense that produced the win.

Arizona State (16-9, 6-7) tied its season low in points and finished 21 points below its average. The Sun Devils shot 22.7 percent in the second half and 33 percent for the game including 6-of-25 from 3-point range. Freshman James Harden, who leads the Sun Devils with an 18.0 average, had 10 points on 3-of-11 shooting.

Harden was bothered by an injured wrist and tight back, coach Herb Sendek said.

"We couldn’t get to the basket and we couldn’t get to the line," Sendek said, although the Sun Devils made all 11 of their free throws. "Against a team like WSU you have to make your shots and we didn’t."

Sendek also pointed to 13 turnovers, including eight steals by the Cougars.

"Every turnover led to an easy basket for Washington State," he said.

Washington State, which is third in the nation in scoring allowing 55 points per game, swept the two-game series with Arizona State for the second straight season.

The Cougars won despite a late second-half scoring drought that saw them held without a field goal for 6 minutes. They shot 43 percent, but went 17-of-24 from the free throw line.

A 3-pointer by Ty Abbott, his first points of the game after scoring 30 in the previous outing, brought Arizona State within 43-40 with 7:42 left. But the Sun Devils did not make another field goal.

Then came Baynes’ steal and dunk with 5:57 left.

"It got the crowd in a frenzy. It got us on the bench in a frenzy," Washington State’s Robbie Cowgill said. "It’s hard not to look at Baynes and smile."

Harden was fouled on a 3-point attempt and made all three free throws to bring Arizona State within 45-43. Kyle Weaver then made two free throws for Washington State.

Two minutes passed without a basket before Daven Harmeling of the Cougars hit a 3 from the corner for a 50-43 lead with 2:20 left.

In the first half, the Cougars shot 54 percent to lead 30-26.