They traded blows for 45 minutes, fighting for first place like Pac-10 heavyweights should.

Washington threw the first punch. Arizona State countered. And so forth.

But as the Hec Edmundson Pavilion din grew louder, as ASU star James Harden went to the bench after picking up his fifth foul, it was the Pac-10’s first-place team that threw the final haymaker in a game that may very well have decided the conference championship.

It took a frantic end to regulation and an overtime, but the No. 21 Huskies held off the No. 14 Sun Devils 73-70 in front of a capacity crowd at Hec Ed last night to take an iron-clad grip on the conference’s top spot.

Now 1½ games ahead of ASU, California and UCLA, Washington needs only to defeat Arizona Saturday to clinch at least a tie of the Pac-10 regular season title.

And they did it without containing either Harden or talented big man Jeff Pendergraph, turning it over 15 times and shooting just 38.3 percent.

“We were able to somehow find a way to win,” UW head coach Lorenzo Romar said.

They did it by getting Jon Brockman involved, packing it inside in the second half and getting Pendergraph in foul trouble. Brockman finished with 21 points and 11 rebounds.

“This was a very mature win,” Brockman said. “This was a gutsy win. The last two years there is no way we could have been able to pull it out.”

Harden scored 15 of his 19 points in the first half, nine of them in the last four minutes. Washington led 35-34 at halftime. Pendergraph finished with 24.

Before Harden got going, though, it looked like this one might be over early. The Huskies ran out to a 21-8 lead, using a 14-1 run fueled by pressure defense and easy looks at the rim. Quincy Pondexter scored six points in the first seven minutes, and Brockman led the UW in the first half with 11 points and six rebounds.

A 19-11 ASU run made things close from that point forward.

The back-and-forth kept things interesting and kept things close. But Washington was in control until ASU finally broke through, taking its first lead since 2-0 with a bucket by Pendergraph, pulling ahead 52-51 with 6:39 to go.

He added another with 5:03 left. Then Rihards Kuksiks buried a 3-pointer on the Sun Devils’ next possession, giving ASU its largest lead of the game at 56-52.

But it was Dentmon who keyed a mini-comeback by the Huskies in the final two minutes of regulation, sinking a 3-pointer — his first of the game after an 0-8 start — and banking in a shot off the glass to give the UW a 61-59 lead.

Then came Dentmon’s slip-up. After a missed shot by Harden, the UW corralled the rebound and got the ball to Dentmon, who promptly had his pocket picked by Harden, who tied the game with a dunk with 13 seconds left.

Dentmon turned it over trying to get a shot off at the buzzer, sending one of the Pac-10’s craziest games this season into overtime.

“It was a selfish move on my end,” Dentmon said. “I regret that. I almost gave it away. I put blame on myself for that part. I almost gave the game away.”

But the Huskies (21-7, 12-4 Pac-10) never trailed in the extra frame. They sprinted out to a four-point lead, extended it to five, then held on as ASU was forced to foul down the stretch, solidifying their place at the top of the Pac-10.

Reach reporter Christian Caple at sports@dailyuw.com.