TUCSON – The last time USC won a men’s basketball game at Arizona, Ronald Reagan was president, the Berlin Wall stood tall and the first “Back to the Future” movie was No. 1 at the box office. Or, in basketball sense, Michael Jordan had yet to win an NBA Championship or scoring title, Tim Floyd was an assistant at Texas El-Paso dreaming of his first head-coaching job and Abdoulaye N’diaye was the only current Trojan player alive. Young and Stewart led USC with 26 points apiece, and Pruitt added 17 points and four steals. “I think it’s the best the three of them have played in sequence since we’ve been here,” Floyd said. Stewart didn’t start because he missed two days of practice this week, first to go to Mississippi for the funeral of his great-grandfather and then with a sore throat. But he provided a spark the moment he took the court, hitting a 3-pointer to start a 10-0 run that erased an early 19-10 deficit. Stewart was a factor at the end, too. He took two steps to his right and drained a jump shot to put USC ahead for good at 74-73 with a little more than three minutes remaining. He made 11 of 15 shots. Young extended the lead from there, nailing a jumper while being fouled and completing the 3-point play. Then Pruitt leaped high to steal an overhead pass from Mustafa Shakur and convert two free throws that gave USC a six-point advantage with just more than a minute remaining. Arizona is the sixth-ranked team that USC has beaten this season, making the Trojans a virtual lock for the NCAA Tournament. One more victory Sunday at Arizona State, to give the Trojans 20 victories, might close the deal. “We all knew this was the game to get us in the tournament,” said Young, who made 9 of 13 shots. “We came together before the game and talked about it.” Floyd had downplayed the 21-game losing streak in Tucson all week, saying his teams were 0-1 at McKale Center. But the sweep of Arizona impressed him. At his first press conference when hired as coach, Floyd called the Wildcats the barometer in the Pac-10. “It’s (bigger) to win against Arizona, who I consider the measuring stick in the league,” Floyd said. “No one has sustained a better program in the country than Lute Olsen. I feel proud of the team win.” [email protected] (818) 713-3607 160Want local news?Sign up for the Localist and stay informed Something went wrong. Please try again.subscribeCongratulations! You’re all set! A lot has changed since Jan. 17, 1985, and USC showed Thursday that the state of Trojans basketball has earned a spot on that list. The hot shooting of Nick Young and Lodrick Stewart, along with pocket-picking defense from Gabe Pruitt, led No. 22 USC to an 80-75 victory over No. 19 Arizona, breaking the Trojans’ 21-game losing streak at McKale Center. “It means a lot,” Young said of the victory. “I wasn’t born the last time they won here. I was born a few months later. It’s something I’ve been dreaming about all week, to come in and get this win.” With the victory, USC (19-7, 9-4) extended its third-place lead in the Pacific-10 Conference to 1 1/2 games over Arizona (17-8, 8-6) and Oregon. USC’s first win at Arizona in 22 years didn’t bring much of a celebration. Young hugged Daniel Hackett at midcourt, tossed the ball high in the air and pumped his fist while heading toward the bench. Most of the players just walked to the locker room. The Trojans had beaten Arizona two games in a row, both in Los Angeles, giving hope that this could be the year for USC to end the streak.