LOS ANGELES (Ticker) -- Arizona freshman Mustafa Shakur dealt a fatal blow to Southern California's season.
Shakur nailed a 3-pointer at the buzzer to give the 16th-ranked Wildcats a 79-76 victory that ended the Trojans' season in the Pac-10 Conference tournament quarterfinals.
Arizona (20-8), a first-round loser to UCLA last year, will face Washington in the semifinals. The Wildcats lost twice to the Huskies during the regular season.
Southern California (13-15) was hoping to repeat its run to the title game each of the previous two years. Freshman Lodrick Stewart scored six straight points to forge a 76-76 tie with 74 seconds to go.
After the Trojans committed a shot clock violation to squander a chance to go ahead with four seconds left, the Wildcats were forced to inbound from under their own basket. Channing Frye threw a pass to Shakur, who raced upcourt as the clock ticked down.
As Shakur continued his dash, USC defender Desmon Farmer retreated. The freshman, a 37 percent shooter from the arc, pulled up and let fly with an uncontested jumper that swished through as time expired.
"It was designed to be a full-court pass to Hassan (Adams), but I knew that if I got (the shot), I was going to make it," Shakur said. "I was just thinking which direction I wanted to go with (the ball) when I got it."
Farmer's gaffe was part of a miserable night in his final game. The senior swingman, who scored 40 points in a win over Arizona on January 15, made 2-of-20 shots for four points. He missed all 12 3-pointers.
"It wasn't my night," Farmer said. "That's the way games go, you can't predict. Everything felt good. I definitely feel this loss."
Adams, a Los Angeles native, collected 21 points and 14 rebounds to offset a rough shooting night by Salim Stoudamire, who made 3-of-15 shots for eight points. Shakur finished with 16 points, seven rebounds and six assists.
"We were very fortunate to get this one," Arizona coach Lute Olson said. "Salim had a really bad shooting game, but on the other hand, he caused Farmer to have a worse one, I guess."
Arizona appeared intent on turning the contest into an early rout, bolting to a 21-9 lead on Adams' basket less than eight minutes into the game. The Wildcats led by as many as 13 points before settling for a 40-36 halftime edge.
Errick Craven scored six points to key a 8-1 second-half surge that opened a 44-41 lead for the Trojans, and the game stayed close the rest of the way.
Stewart matched a season high with 20 points and Craven netted 18 for USC, which shot 36 percent (29-of-80). The Trojans were doomed by Farmer's numerous misfires.
"Everyone can sit there and second-guess what we could do, but what it comes down to is that Arizona is a top-25 team and they have guys that can make that shot," USC coach Henry Bibby said. "I give a lot of credit to them."