No. 4 Arizona puts on a defensive show in Pac-12 opener, blows out Utah 71-39

Utah's Dallin Bachynski, left, and Arizona's Kaleb Tarczewski scramble for a loose ball during the first half of an NCAA college basketball game in the quarterfinals of the Pac-12 Conference tournament, Thursday, March 13, 2014, in Las Vegas. (AP Photo/Julie Jacobson) (The Associated Press)

Arizona's Aaron Gordon (11) puts up a shot past Utah's Jordan Loveridge during the first half of an NCAA college basketball game in the quarterfinals of the Pac-12 Conference tournament, Thursday, March 13, 2014, in Las Vegas. (AP Photo/Julie Jacobson) (The Associated Press)

Nick Johnson scored 14 points, T.J. McConnell added 13 and No. 4 Arizona overwhelmed Utah defensively in a 71-39 rout on Thursday to match the most lopsided game in Pac-12 tournament history.

After playing two close games against Utah during the regular season, top-seeded Arizona (29-3) opened the tournament with a spirit-crushing defensive performance.

Energized by a raucous crowd that made it feel like the McKale Center, the Wildcats provided a glimpse of what can happen when one of the nation's best defenses gets rolling.

Arizona ran through the record book against Utah (21-11), 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.