Arizona center Oumar Ballo (11) exults after scoring and picking up the foul against UCLA in the second half of their Pac 12 game at McKale Center, Tucson, Ariz., January 21, 2023.

 Kelly Presnell / Arizona Daily Star

The Arizona Wildcats reinvented themselves over the weekend at McKale Center — to such an extreme that even their creator did a double-take.

“I look at that score,” UA coach Tommy Lloyd said Saturday, “and I wonder if they stopped the game at halftime.”

The final score was Arizona 58, UCLA 52. No joke.

Yes, the team that started the season with a 117-point effort against Nicholls State — a team that ran the most efficient offense in Division I until hitting a New Year’s slump — pulled out the biggest win of its season mostly by playing good, old-fashioned, hard-nosed defense.

No. 11 Arizona, which also beat USC 81-66 on Thursday while holding the Trojans to just 36.9% shooting, this time kept the fifth-ranked Bruins to a season-low 31.3% from the field. It was similar to the way the Wildcats relied more on defense in pulling out a 76-66 homecourt win over UCLA last season at McKale but, again, a more extreme version.

Arizona guard Courtney Ramey (0) gestures to the crowd after hitting a three against UCLA in the second half of their Pac 12 game at McKale Center, Tucson, Ariz., January 21, 2023.

“We don’t have many games in the 50s, so to be able to win a game in the 50s against a team like UCLA says something about our guys,” Lloyd said.

Before Saturday, the Wildcats had scored under 60 points only once under Lloyd, a 75-59 loss at UCLA last season. Since Lloyd took over in April 2021, the Wildcats had put up an average 84.0 points last season and until Saturday were averaging 84.6 points this season.

“I think we proved that we can win low-scoring games,” UA guard Kerr Kriisa said. “Everyone keeps talking about offense and offense and offense, but nobody really talks about how good our defense is. I think today we really proved we were gritty.”

Even during the slower-paced Sean Miller era, 50s-ish games weren’t all that common for the Wildcats. They hadn’t won a game while scoring under 60 points in seven years, since beating — guess who? — UCLA 57-47 at McKale Center during the 2014-15 season.

But that 2014-15 team, which went on to win the Pac-12 and reach the NCAA Tournament Elite Eight for the second straight season, ranked No. 3 in Kenpom’s adjusted defensive efficiency. They were used to stopping people.

These Wildcats were not always that way. Their defensive efficiency rated in the 50s and 60s until their performances this weekend moved them up to 44.

“I think you put the two games together, and it was our best defensive weekend,” Lloyd said.

Arizona guard Cedric Henderson Jr. (45), left, and UCLA forward Kenneth Nwuba (14) chase a loose ball in the first half of their Pac 12 game at McKale Center, Tucson, Ariz., January 21, 2023.

Lloyd said he thought the Wildcats had “real, real defensive potential,” but it didn’t come out fully until this week — after Arizona had played poorly in three of its first four games in 2023, including a home loss to Washington State on Jan. 7 and an 87-68 loss at Oregon a week later.

While Lloyd said the Wildcats have simply been more “attentive” defensively, he also said part of the difference might have had to do with a lineup change Thursday, when he swapped Cedric Henderson for Pelle Larsson at small forward.

That move paid off on the offensive end Thursday against USC, when both Larsson (15 points) and Henderson (11) scored in double figures. But Lloyd saw a defensive benefit on Saturday.

“When you’re bringing Pelle off the bench, you’re arguably bringing one of your better defenders off the bench, who is very versatile,” Lloyd said. “He can guard fours. He can guard point guards. He can guard centers. And Cedric has been playing with great defensive energy as well in that starting role.”

Then there’s the production of guard Courtney Ramey on both sides of the ball. Not only has Ramey snapped out of a New Year’s shooting slump, but he also helped made life difficult for the well-regarded point guards who entered McKale this week.

USC’s Boogie Ellis shot just 2 of 11 from the field while scoring 11 points on Thursday, while UCLA’s Tyger Campbell was just 5 for 18 while scoring 13 points on Saturday.

“I don’t know what his stats were, but his impact on the game was significant,” Lloyd said of Ramey. “He hit some dagger 3s, and his defense was outstanding in both games.”

Of the rest of the Bruins, only reserve wing Will McClendon (2 for 4) and center Adem Bona (5 for 6) shot over 40% from the field. Jaylen Clark and Jaime Jaquez had to work hard to reach double figure scoring. Clark had a double-double of 12 points and 10 rebounds but shot 4 for 13, while Jaquez shot 5 for 17 overall and just 1 of 6 from 3-point range.

Also critical for Arizona: UCLA’s best 3-point shooter, David Singleton, missed all three 3s he took and was 0 for 5 overall.

While it might have looked like the Bruins just missed some good looks at the basket along the way, UCLA coach Mick Cronin suggested it was more than that.

Arizona guard Kerr Kriisa (25) flips a pass over UCLA guard Tyger Campbell (10) bringing the ball up court in the first half of their Pac 12 game at McKale Center, Tucson, Ariz., January 21, 2023.

“When you struggle offensively, something with the other team’s defense caused it,” Cronin said. “Even if it’s open shots, they’ve got you sped up just enough, rattled just enough. I think you have to give the other team credit.”

Cronin appeared more disappointed in the Bruins’ defense, even though Arizona shot only 38.8% itself, relying heavily once again on big men Oumar Ballo (16 points and eight rebounds) and Azuolas Tubelis (11 points and 10 rebounds).

Cronin said the Bruins “didn’t play hard until the game was over,” though UCLA actually led most of the first half before Arizona took double-digit leads in the second.

Cronin also took little consolation in the success of a late-game press that helped the Bruins go on an 8-0 run and cut Arizona’s lead to just 56-52 with 26 seconds left.

“It shows you what you’re capable of when you play with your heart and intestinal fortitude,” Cronin said. “If you only play with your mind, your mind is on your missed shots instead of your effort.”

Arizona led 56-44 entering the final two minutes, but two turnovers from Larsson led to UCLA baskets that cut the lead to 56-50. Then, two more UA turnovers led to a layup from Bona, and the Bruins had cut it to four.

With 26 seconds left, Kriisa and the Wildcats’ offense were under pressure again to at least hang on. They wound up getting the ball to Tubelis under the basket.

“I mean, we had three turnovers earlier,” Kriisa said. “So one time it has to work, right?”

Arizona center Oumar Ballo (11) takes an elbow trying to drive on UCLA forward Kenneth Nwuba (14) in the first half of their Pac 12 game at McKale Center, Tucson, Ariz., January 21, 2023.

Jaquez, however, blocked Tubelis. Larsson rebounded the shot and initially was given credit for a basket via a goaltending call. But officials reviewed and reversed the call. That left the game still at 56-52.

But then the Bruins missed again. Neither Campbell nor Jaquez could make inside desperation shots on UCLA’s final possession. Larsson was fouled and hit two free throws for the Wildcats’ final points.

That is, points No. 57 and 58. Just enough to snap UCLA’s 14-game winning streak and move Arizona to 17-3 overall and 6-3 in the Pac-12, where the Wildcats are now two games behind the Bruins (17-3, 8-1).

Thanks to their defense, the Wildcats had just enough to win the game, just enough to stay in the conference race and just enough to learn a lesson that could help them climb even higher.

“At the end of the game, we should have punched them out,” Kriisa said. “We were a little bit shaky with the press, even though we knew it was coming. We have a lot of things to clean up, but I’m really excited.”

No. 11 Arizona 58, No. 5 UCLA 52

UCLA (17-3)

Bona 5-6 1-2 11, Campbell 5-18 1-2 13, Clark 4-13 3-4 12, Singleton 0-5 0-0 0, Jaquez 5-17 1-3 12, Nwuba 0-0 0-0 0, McClendon 2-4 0-0 4, Andrews 0-4 0-0 0, Etienne 0-0 0-0 0. Totals 21-67 6-11 52.

ARIZONA (17-3)

A.Tubelis 5-15 4-6 14, Ballo 4-8 8-11 16, Kriisa 2-9 1-1 7, Ramey 4-6 0-0 11, Henderson 0-1 0-0 0, Larsson 3-7 2-2 8, Boswell 1-3 0-0 2. Totals 19-49 15-20 58.

Halftime: Arizona 26-23. 3-Point Goals: UCLA 4-20 (Campbell 2-4, Clark 1-3, Jaquez 1-6, Andrews 0-2, McClendon 0-2, Singleton 0-3), Arizona 5-18 (Ramey 3-5, Kriisa 2-8, Henderson 0-1, Boswell 0-2, Larsson 0-2). Rebounds: UCLA 36 (Jaquez 11), Arizona 35 (A.Tubelis 10). Assists: UCLA 13 (Campbell 7), Arizona 13 (Larsson 3). Total Fouls: UCLA 16, Arizona 13. A: 14,688 (14,644).

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Contact sports reporter Bruce Pascoe at bpascoe@tucson.com. On Twitter: @brucepascoe