Arizona's top three scorers heading into Monday night were freshmen.

But it's a junior who is making it all go.

Junior point guard Parker Jackson-Cartwright posted the first double-double of his career -- 15 points and a career-high-tying 11 assists -- as the No. 8 Wildcats survived an unexpected battle from Northern Colorado, winning 71-55 in Tucson, Ariz.

Jackson-Cartwright committed only one turnover, gave Arizona the lead for good with a driving three-point play with about 12 minutes left, and helped Arizona (4-0) settle into a zone-busting offense late in the game.

Freshman Lauri Markkanen benefited from several Jackson-Cartwright setups, as the 7-footer from Finland had 17 points and a career-high 13 rebounds.

Jackson-Cartwright has 23 assists and five turnovers this season.

"I can't say enough about Parker tonight," Arizona coach Sean Miller said. "I thought he was the best player on the court for us.

"He really is settling in and I'm happy for him because he's worked really hard. He's so valuable in making the game easier for our team."

Northern Colorado (1-3) was coming off an 88-72 loss at Santa Clara but made things uncomfortable for Arizona most of the night. The Bears used a 2-3 zone that flummoxed the Wildcats early, and guards Jordan Davis and Chaz Glotta did all they could on the offensive end.

Davis, who entered averaging 23.7 points, scored 20.

"I think he has a chance to be an NBA point guard," Miller said. "He's just very, very strong. He dominates the game in many ways. It's his scoring, his play-making, his ability to pick up fouls."

Glotta hit 5 of 11 3-pointers and finished with 15 points. He and Davis combined to take 31 of Northern Colorado's 55 shots.

"To come in to one of the top venues in college basketball and play like we did against, really, a top five team in the country and against one of the best coaches is a testament to the strides this team is making," Bears coach Jeff Linder said.

Northern Colorado led 39-37 on a contested, fall-away 3-pointer by Glotta with 14:11 left, but Davis picked up his fourth foul on a charge call with 12:25 remaining and headed to the bench.

Arizona took advantage. Jackson-Cartwright drove to the basket for a three-point play for the 17th -- and final -- lead change of the game. Markkanen hit a jumper for a 42-39 lead and then drained a 15-footer for a five-point edge with 10:20 to go before Davis got back into the game.

Arizona never led by more than four points in the first half and trailed for the final 5:41 after a 3-pointer by Glotta gave the Bears a 25-24 edge.

The Wildcats, bothered by the zone, made 11 of 30 shots from the field in the first half, including 3 of 10 from 3-point range. The smaller Bears led 31-30 at the half.

"It was the first time we went against a zone," Miller said. "It felt funny in the first half. We have a ton of new faces out there in different roles, but in the second half we really settled in. In the last 10 minutes, we got great shots."

NOTES: Arizona G Allonzo Trier watched the game from the bench in street clothes, missing his sixth consecutive game, including two exhibitions. School officials have not commented on the nature of his absence, nor a timetable for a potential return. Trier averaged 14.8 points per game as a freshman last season. ... Arizona G Kadeem Allen was back in the starting lineup. He missed the second game of the season because of a sprained left knee and played only four minutes on Friday night against Sacred Heart. He had 10 points in 35 minutes. ... The Wildcats have won 36 consecutive nonconference home games. ... Northern Colorado is on a five-game road trip that will end Nov. 29 at Oklahoma. ... The next stop for the Bears and Wildcats is the bracketed part of the Continental Tire Las Vegas Invitational on Thursday and Friday.