BERKELEY, Calif. -- Guard Justin Cobbs scored Cal's last 12 points, including the winning 17-foot jumper with 0.9 of a second left, as the Bears beat No. 1 Arizona 60-58 on Saturday night, handing the Wildcats their first loss of the season.

"This is a big deal," said Cobbs, who finished with 19 points and seven assists. "It was the No. 1 team. If that's not a big deal, I don't know what is."

Cal (15-7, 6-3) halted a three-game losing streak and beat a No. 1 team on the Bears' home court for the first time ever. The last time Cal beat a No. 1 team was 1994, when the Bears upset UCLA at Oakland Coliseum.

A poor game by guard Arizona guard Nick Johnson, the team's leading scorer, and a significant foot injury that sidelined starting forward Brandon Ashley two minutes into the game made things difficult for the Wildcats (21-1, 8-1 in the Pac-12). Ashley is likely to be sidelined for a while, perhaps even the rest of the season.

Johnson, who entered the game averaging 16.7 points, had just four points on 1-for-14 shooting from the field.

"It just wasn't his night," Arizona coach Sean Miller said.

Johnson made a pivotal 10-foot runner in the lane in the closing minutes of Arizona's comeback victory over Stanford on Wednesday but missed an almost identical shot with 16 seconds left on Saturday with the score tied 58-58.

After Johnson's miss, Cal did not call a timeout and Cobbs worked his way off a screen from forward David Kravish. Cobbs then pulled up along the left side and buried the go-ahead shot with less than a second remaining.

"The guy contested him pretty good; they were there," Cal coach Mike Montgomery said. "It was just pure."

The Cal fans rushed the court but had to be cleared as Arizona called timeout to set up a last attempt. Arizona failed to get off a final shot and fans stormed the court again.

"Obviously, I don't think any of us thought we were going to go 40-0," Miller said. "The thing about tonight's game was that it was eerily similar to a lot of games this season where we have made plays at the end to win, whether it was a defensive stop or a big shot."

Miller seemed less concerned about the result than in the condition of Ashley, who is the team's second-leading scorer, averaging 12.0 points.

"It looks like a broken foot, although I can't say that for sure yet," Miller said. "It's certainly an injury that will keep him out for a time, if not the entire season."

The Wildcats got 18 points from center Kaleb Tarczewski, who was 12-of-12 from the line. In fact, the Wildcats hit all 16 of their free throws but shot just 32.3 percent from the field.

Arizona freshman Aaron Gordon was just 4-for-14 from the field and is 9-of-37 in the past three games. He did have 13 rebounds, though.

Arizona trailed nearly the entire game and by as many as eight points with 11 minutes left but nearly pulled it out.

"If you look at our shooting percentage, Nick's game and the injury to Brandon, you think, 'How in the world were we there at the end?'" Miller said.

Cal nearly let the Wildcats off the hook. Kravish had 14 points and 11 rebounds, but it was Cobbs who saved the Bears at the end.

Cobbs, who scored three points on 1-of-4 shooting from the field in the first half, was the only Cal player who scored in the final 11 minutes.

His two free throws at the 11:00 mark boosted the Bears' lead to 50-42. But Tarczewski gave Arizona its first lead since early in the first half when he made a 6-foot shot with 4:18 remaining for a 56-54 advantage.

Cobbs tied it 58-58 with two free throws with 2:29 to go, and neither team scored again until Cobbs' game-winner.

"I didn't really notice I scored our last 12 points until somebody mentioned it," Cobbs said. "It just happened that I got it going."

NOTES: Arizona began the game as one of three unbeaten Division I teams, along with Syracuse and Wichita State. Last season, there were no unbeaten teams as of Feb. 1. ... The Wildcats started the day ranked 108th nationally in scoring offense but were fourth in scoring defense, yielding just 56.1 points a game. ... Cal entered the game with a 2-24 record against No. 1 teams and had never beaten a top-ranked team on the Bears' home floor. The two only wins over a No. 1 team came against Cincinnati in the 1960 Final Four at the Cow Palace in San Francisco and against UCLA at Oakland Coliseum in 1994. ... Two of Arizona's starters are from the San Francisco Bay Area: F Brandon Ashley, who attended Oakland Bishop O'Dowd High School, and F Aaron Gordon, who attended Archbishop Mitty High School in San Jose.