SAN FRANCISCO -- Dior Lowhorn swears that when he's out shooting 3-pointers after practice, he routinely knocks down 50 of 70. As for why he's been so inconsistent from long range this season, he says that's all psychological.
His terrific performance against the West Coast Conference's top team ought to do him some good.
"Oh, man, that's the biggest win since anybody's been here," Lowhorn said.
Matt Bouldin scored Gonzaga's only three baskets in the extra session and the Bulldogs (17-4, 6-1 West Coast Conference) lost for the first time in 28 regular-season WCC games.
Angelo Caloiaro made a 3 with 32.8 seconds left that helped the Dons end a nine-game skid in the series.
Many in the raucous, near-capacity crowd of 4,114 at Memorial Gym rushed from the stands after the final buzzer. Fans and USF players danced on the court for several minutes in a wild celebration until police and security put an end to the frenzy.
"As a coach, no question this is as good a feeling as I've felt," second-year USF coach Rex Walters said. "Everybody is going to look at this game and say this will be the highlight of our season. I said to the guys, 'Let's work hard so it isn't."'
Lowhorn went 5 of 7 on 3-pointers after coming in 8 for 47 from long range this season, sending the Dons (8-14, 3-4) to their first win over Gonzaga since a 73-70 victory over the then-No. 11 Zags on Jan. 20, 2005. He pumped his fist and cheered when he hit big shots.
"We came together. We wear our emotions on our sleeves," Lowhorn said. "We celebrated. You always want to beat the No. 1 team in your conference. The only team people think about is Gonzaga."
Lowhorn hit a tying 3-pointer with 9.8 seconds left in regulation after a miss moments earlier and Steven Gray missed a 3 on the other end. Kwame Vaughn's 70-foot prayer for USF bounced out off the backboard and rim at the buzzer.
Rashad Green, moved into the starting lineup by Walters to shake things up, scored 15 points and Caloiaro had 11 with three 3s. USF ended a three-game losing streak.
Gray missed two free throws in OT for the Zags after making two with 25.3 seconds left in regulation.
"We've been putting ourselves in that situation it seems like just about every game," Gray said. "We're not playing with the energy that we need and it finally caught up to us. Hopefully it will be a wake-up call."
Bouldin finished with 15 points, standout Zags freshman Elias Harris scored 21 and Robert Sacre had 19.
Gonzaga had won nine straight overall and 22 in a row against league opponents. The Zags had to rally from 14 points down in the second half of their 71-64 win at Santa Clara on Thursday night and then faced another tough one on the Hilltop.
"We've been playing with fire a little bit," coach Mark Few said. "Everybody's been playing us tough and we've been able to make a lot of plays at the end of games. This time USF made some big plays."
The teams traded clutch shots down the stretch in regulation. After Lowhorn and Dontae Bryant knocked down back-to-back 3-pointers to give USF a 60-57 lead with 4:41 to play, Bouldin swished a 3 from the right wing moments later.
Lowhorn, the WCC's leading scorer the last two seasons, tied it at 48 with his driving baseline scoop shot with 10:22 to go. Caloiaro put USF ahead the next time down with a 3-pointer.
Lowhorn overcame early foul trouble. He was whistled for his third foul with 2:28 left in the first half and took a seat.
"Dior played big-time," Bryant said. "We'd been waiting for a breakout game from him."
After Demetri Goodson's 3-pointer with 17:03 left gave Gonzaga its biggest lead at 42-32, USF answered with a 9-0 run to get right back in it. Caloiaro knocked down a 3 at 14:56 to make it 42-41 and Gonzaga went 3:15 without scoring.
The Bulldogs conclude the conference season with five of their final seven games at home in Spokane, Wash. They are picked to win their 10th straight WCC regular-season crown.
"Nothing's sacred," Few said. "We've just got to get back to playing the best we can at what we do best, and we've kind of gotten away from that a little bit."
After Gonzaga hosts Portland on Thursday, the Zags hit the road for a key non-conference game at Memphis next Saturday.
The Dons were outrebounded for only the fourth time in their last 16 games, 39-34.
Both teams were clicking offensively early before cooling off late in the first half. Gonzaga shot 48.4 percent on the way to a 33-26 lead at the break. While the Zags led by as many as nine, there were four ties and five lead changes in the opening 20 minutes.