Watch Now:

TUCSON, Ariz. -- Arizona-UCLA has been one of the best, most enduring rivalries in the West for about three decades. Saturday's matchup arguably is one of their most-hyped meetings ever.

These national powers are peaking at the same time. No. 4 Arizona (26-3, 15-1 Pac-12) holds a one-game lead over Oregon in the conference race. No. 5 UCLA (25-3, 12-3) is in third place and leads the nation in scoring at 92.1 points per game.

The teams are meeting for the first time when both are ranked in the top 5. This is only the seventh matchup of top 5 teams in conference history, and the first since 2008.

ESPN's College GameDay show is in Tucson to further spotlight this game, which tips off at 10:15 p.m. ET from McKale Center.

"I hope they're excited," Arizona coach Sean Miller said of his players after Thursday night's 90-77 victory over USC.

"I probably ruined their excitement a little bit after the game, but that's kind of my job. To allow them to be the most successful, they have to be really focused on the task at hand. If you start to get too excited about the game and everything about it, you end up coming unglued or have that anxiety where you're just not yourself."

Arizona won the season's first meeting, 96-85, in Pauley Pavilion on Jan. 21. The Wildcats' guards often had easy drives to the basket as the team rolled to its highest point total of the season.

Fast-paced UCLA, led by freshman point guard Lonzo Ball, has had issues with its defense at times this season, but the Bruins have been better recently, holding five consecutive opponents -- including Oregon -- to no better than 42 percent shooting.

USC shot 33.8 percent last week against UCLA, which has won six in a row.

"We're on a good roll right now," Bruins coach Steve Alford told ESPN.

"The thing that I have been really pleased with in the month of February, our guys have really improved defensively as a team. We're mixing some things up, kind of keeping them engaged, because they're such an offensive group and we score at such a high level.

"If our defense can continue to improve like it has done in February through six games, then we have a chance to do some special things."

Arizona is led by freshman 7-foot forward Lauri Markkanen, who is averaging 15.6 points, shooting 45.4 percent from 3-point range and has recently begun to show more toughness around the basket. Guard Allonzo Trier scored a season-high 25 vs. USC and is averaging 15.0 points.

He returned from a 19-game season-opening NCAA suspension for performance-enhancing drugs in the first game vs. UCLA. He scored 14 points.

UCLA leading scorer is freshman forward T.J. Leaf (17.0), followed by guard Bryce Alford (16.2, 45.5 percent shooting), but Ball makes it all go. He averages 15.0 points, 7.5 assists and 6.3 rebounds.

"Just proud of him. He's such a special player," Alford said.

"He makes guys around him better. And what we've seen here in February is now he makes guys around him better defensively. That's just how special Lonzo is. He impacts every area of the game at a high level."

Arizona has won 70 of its past 71 games at McKale Center. With a victory Saturday, the Wildcats will be one win away from an outright Pac-12 title.

"We're going to have to play with incredible effort and incredible togetherness," Miller said of the matchup against UCLA. "And even with that, they're still going to score. We enjoy the challenge, but it's an immense challenge."

Copyright 2017 by STATS LLC. Any commercial use or distribution without the express written consent of STATS LLC is strictly prohibited.