TUCSON, Arizona (Ticker) -- Thomas Kelati shot down the streak.
Kelati made seven 3-pointers and scored 22 of his 27 points in the second half as Washington State ended a 38-game losing streak against No. 11 Arizona with a stunning 70-63 upset in a Pac-10 Conference matchup.
It marked the Cougars' first win against their conference rivals since a 65-63 overtime victory on January 30, 1986. The Cougars also stopped a 20-game losing streak in Tucson dating to a 51-49 victory on January 14, 1984.
"It was pretty emotional," said Kelati, who matched his career high for points set last season against Arizona. "There were tears from the coaches and players because we never expected this to happen."
The Cougars also stopped a 48-game losing streak against ranked opponents dating to victory over No. 25 California on February 22, 1997.
Kelati had a lot to do with ending the Cougars' frustration as he made six of his 3-pointers in the second half. The senior's biggest shot from the arc came with 50 seconds left and snapped a 63-63 tie. He added two foul shots 18 seconds later.
"Kelati was superb," Washington State coach Dick Bennett said. "We've been on him to catch and shoot. He did it a couple of times in a row and it worked. I can usually tell from the spin of his shot if it will be good, and it usually was."
Freshman Derrick Low went 4-of-4 from the arc and scored 13 points for Washington State (9-9, 4-5 Pac-10), which controlled the contest with its methodical offensive tempo and deadly outside shooting. The Cougars went 12-of-21 from the arc.
"This win means a lot," Bennett said. "To go on the road and win at this level is very significant. This tells people we are moving in the right direction."
Mustafa Shakur netted 12 points to lead five players in double figures for the Wildcats (17-4, 7-2), who were coming off Thursday's 91-82 home win over No. 10 Washington.
Arizona coach Lute Olson was critical of his upperclassmen.
"We had problems with out veterans," Olson said. "They should know what it is to have Arizona on their chest. I'm disappointed. We better do some soul searching, individually."
A heavy underdog, the Cougars trailed by just one point at halftime and took a 45-41 lead with 13:50 remaining on Chris Henry's layup.
But Hassan Adams had a dunk off a fast break to trigger a 10-0 run for the Wildcats that Shakur capped with a layup with 9:22 left for a 51-45 advantage.
Kelati helped the Cougars regain their composure, nailing a jumper and 3-pointer. His shot from the arc with 4:43 left gave the Cougars a 58-57 lead.
After Ivan Radenovic - who had 11 points and 10 rebounds - made two foul shots with 3:46 left to give Arizona back the lead, Kelati responded 38 seconds later with another shot from the arc.
Entering the contest third in the country in scoring defense by allowing 55.4 points per game, the Cougars contained sharpshooter Salim Stoudamire, who scored 11 points and made just 4-of-14 shots - including missing all five of his attempts from the arc.
"I just feel that we didn't make any shots," Stoudamire said. "We just couldn't make anything the last two minutes and that's why we lost."
Stoudamire averaged 26 points on 55 percent shooting in his last five games. He made 19-of-33 from the arc in that span.
Channing Frye added 11 points and Adams 10 for Arizona, which shot 46 percent (22-of-48) and went 15-of-21 at the free-throw line. The Wildcats went 38-of-40 at the line in Thursday's win.
"They outplayed us," Frye said. "We just didn't come to play today. This is definitely a letdown. I think people didn't take this game seriously. Washington State wanted to win more than we did."
Robbie Cowgill netted 12 points and Jeff Varem 10 for the Cougars, who shot 46 percent (25-of-54) and went 8-of-12 at the line.