LAS VEGAS -- T.J. McConnell laid out like a baserunner diving headfirst into a base. He missed the ball, but, after landing with a thud, jumped up and raced the other direction.

Aaron Gordon, who did get the steal because of McConnell's effort, flipped the ball ahead and Arizona's point guard ran under it, scoring an easy basket in transition.

The play, and countless others like it in a spirit-crushing rout over Utah, let the rest of the Pac-12 field -- and the country -- know that one of the nation's best defensive is in high gear for the postseason.

Playing with a feverish intensity from the opening tip, Arizona raced through the record book and overwhelmed the stunned Utes in a 71-39 rout on Thursday to match the most lopsided game in Pac-12 tournament history.

"We were locked in," Arizona coach Sean Miller said. "Everything that we wanted to do defensively, we were able to do it."

Nick Johnson scored 14 points, McConnell 13 and Gordon added 11 for Arizona, which shot 53 percent.

That was just a side note to what the Wildcats were doing defensively.

After playing two close games against Utah during the regular season, top-seeded Arizona (29-3) opened the tournament with a have-to-see-it-to-believe-it defensive performance.

Energized by a raucous crowd that made it feel like the McKale Center, the Wildcats were at their lane-jumping, shot-contesting best against the Utes (21-11) to move into Friday's semifinals against Colorado or California.

Arizona jumped on Utah early and had stamped its name in the record books by then, setting marks for fewest points allowed, fewest field goals (12) and lowest shooting percentage (25).

The Wildcats held the Utes to 13 points in the first half, another record, and matched UCLA's 32-point win over Oregon State in 2006 to move into Friday's semifinals against Colorado or California.

Jordan Loveridge and Delon Wright, Utah's leading scorers, combined for seven points on 1-of-4 shooting and Utah lost by 13 fewer points than its 10 previous losses combined.

"When we get stops and get rebounds and get the push, our athleticism is really at play," Johnson said. "I think finishing with dunks and around the basket gets everybody going.

Arizona had hoped to make a statement in the Pac-12 tournament to earn a No. 1 seed in the NCAA tournament.

The Pac-12 regular-season champion Wildcats certainly did in their tournament opener, playing with an intensity Utah had no chance of matching after playing a close game against Washington the night before.

The crowd at MGM Grand Garden Arena started chants of "U of A! U of A!" long before the opening tip and the Wildcats turned the game into a rout not long after the ball went up.

Racing out for dunks and 3-pointers in transition set up by their climb-in-your-jersey defense, the Wildcats stormed past the Utes with an 18-2 run that put them up 22-6.

Arizona kept its foot on the Utes behind its defense, contesting every shot, pass and dribble.

The Wildcats held Utah to 5-of-19 shooting while forcing eight turnovers in the first half. Loveridge and Wright, who combine for over 31 points per game, took four shots and had no points between them.

"They were really putting on a defensive clinic in the first half," Utah center Dallin Bachynski said.

Second half, more of the same.

Utah missed its first 11 shots -- its first field goal came 9:15 in -- and at one point had five players on the court who had yet to score in the game.

Yep, it was that bad.

The only thing in doubt at that point was whether the Utes would get to 30 points. They got there with 4:17 left, but, boy, was it ugly.

"They took pride in guarding us," Utah coach Larry Krystkowiak said. "They took the life out of us."