TUCSON, Ariz. -- Arizona finds itself in a familiar spot -- at the top of the Pac-12 standings.
Gabe York scored 17 points and the No. 17 Wildcats moved into a share of the conference lead with an 86-80 victory over No. 23 Southern California on Sunday.
Allonzo Trier scored 12 of his 14 in the second half as the Wildcats (21-5, 9-4) held off a rally by the Trojans (18-7, 7-5), who were swept over the weekend in the desert.
Bennie Boatwright, scoreless in Friday night's loss at Arizona State, had 18 points for USC.
Arizona led by as many as 19 in the first half and was up 16 at halftime. USC rallied to cut it to 70-68 with 6:40 to play, but the Trojans missed their next nine shots and the Wildcats pulled away.
Ryan Anderson added 14 points for Arizona, and Mark Tollefsen scored 11 of his 13 in the first half. Jordan McLaughlin had 15 for USC.
Arizona began the weekend two games behind first-place Oregon, but the Ducks were swept at California and Stanford, and the Wildcats beat both Los Angeles schools.
"We expect ourselves to be at the top and competing for the title," Anderson said. "This is what we have done the last couple of years, this is what we plan to do this year."
Arizona has won five in a row since losing at home to Oregon, a game that broke the Wildcats' 49-game winning streak at McKale Center.
But coach Sean Miller was not pleased with the way his team played in the second half. Putting together a complete game, he said, has been a problem all season.
"Our first half was excellent basketball," Miller said, "but we're trying to put both halves together and we have just not been that team this season. We have to eventually become that team because when we get in those elimination moments -- you lose and you go home -- we're going to go home."
Arizona never trailed but had to weather a furious USC rally.
Trailing 46-30 at halftime, the Trojans outscored Arizona 23-9 to cut the lead to 70-68 on McLaughlin's 3-pointer with 6:40 to play.
Dusan Ristic and Kaleb Tarczewski each sank a pair of free throws, Trier hit a 3-pointer as the shot clock wound down and Kadeem Allen made a driving floater in a 9-1 spurt that put the Wildcats back in control 79-69 with 3:36 to play.
The Trojans went 6:07 without a field goal before Boatwright's 3 with 33 seconds left.
"I thought the difference in the game down the stretch was that we missed a lot of easy shots and they made a couple of tough ones," USC coach Andy Enfield said. "To win on the road, especially a place as tough as McKale Center, against a top 15 team in the country, you need to make those shots in the last 5 minutes."
It looked like a blowout in the first half.
The Wildcats, who lost 103-101 in four overtimes at USC on Jan. 9, took apart the Trojans' zone defense, shooting 54 percent to lead 46-30 at the break.
Leading just 22-18 eight minutes into the game, the Wildcats outscored the Trojans 21-6 over the next 10 1/2 minutes. Tollefsen scored 11 in the run, capped by his tip-in that put Arizona up 43-24 with 1:39 left in the half.
Boatwright sank a pair of jumpers to cut the lead to 43-28, then York -- under severe duress at the top of the key -- hit a falling-away 3-pointer as the shot clock expired. A 10-footer by McLaughlin at the halftime buzzer made it a 16-point lead at the break.
USC: The Trojans fell to 1-5 on the road in the Pac-12. ... Boatwright got in early foul trouble for the second game in a row, drawing his second 4:23 into the game. ... The Trojans have lost seven in a row at Arizona.
Arizona: York became the 50th Wildcats player to top 1,000 points in his career. ... It was the first time in nine years that USC and Arizona were both ranked when the teams played. ... The Wildcats are the only team with a winning road record in Pac-12 games.
USC hosts Colorado on Wednesday.
Arizona hosts Arizona State on Wednesday.