Our entire perception of the Pac-12 changed on Saturday.

UCLA, the most entertaining team in the country, and a team that was a No. 1 seed in plenty of bracketology forecasts entering the weekend, is now a team that's two games behind in its own conference. The Bruins are 19-2, still a very good team, but its two losses have come against Oregon and Arizona. And wouldn't you know it: those are the two teams still unbeaten in Pac-12 play.

UCLA's hopes of winning the Pac-12 suddenly seem dim. Arizona's 96-85 win at Pauley Pavilion -- an important detail -- featured the most points scored by Arizona at UCLA since 2004, when U of A put up 107 on the Bruins. The outcome gives Arizona a 12th straight win.

Takeaways

1. UCLA's grips on a No. 1 seed and a Pac-12 title are likely done

Yeah, it's kind of crazy to say it, but I don't think the Bruins can win the Pac-12 now. They're two games behind the Ducks and the Wildcats in the loss column, and they've taken on losses to both teams. I'll get to the 1-seed issue in a second, but follow me here. UCLA's remaining schedule is five at home and five away, but it still has to play at USC and at Arizona. It also hosts Oregon, which should be fully healthy in time for that game, on Feb. 9.

As for Oregon and Arizona, those teams only have to face each other once this season, an important detail. Oregon gets hosting duties on Feb. 4. Also, Arizona has more home games than road games remaining in league play. Also: Arizona looked like a top-10 on Saturday. Also: Arizona's probably going to get even better, because this was Allonzo Trier's first game in uniform this season.

Oregon's schedule does have more road than home games, but the Ducks are so much better on defense than UCLA, and Oregon's offense has flirted with top-30 status all season.

So if UCLA can't win the Pac-12, then it's not going to get a 1 seed. The chase for a 1 this year is going to be so competitive. You can make an argument there are 15 teams right now with legitimate sights on getting to the top line. Many of those teams will take on too many losses to stay in the mix, but UCLA's lack of elite wins (it has one win over a team in the RPI's top 50, a great one at Kentucky, but that's it) is a glaring red flag.

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UCLA is going to have a hard time winning the Pac-12 now. USATSI

2. And now we see that UCLA's lack of defense can be a killer

In many games, UCLA's going to blaze past its opponent because it can score 80 and not break a sweat. Heck, UCLA scored 85 in a loss on Saturday and still looked really good doing it, even if it was far from pretty by the team's standards this season. Against 95 percent of opponents, what UCLA did on offense (32 percent from 3-point range, 79 percent from the foul line, 45 percent from the field, only six turnovers) on its home floor would be enough to get a win.

But allowing Arizona to score a season-high in your building, and letting them do it from close, from far, shoot 50 percent from the field and get 12 second-chance opportunities, it's a killer. Arizona didn't play its best game on Saturday. The team looked really good, but if UCLA had been merely competent on defense, it would have won. UCLA fans have a right to have concerns with this. I don't think it's freak-out time, but fears were materialized on Saturday.

As for Lonzo Ball, he had 24 points, eight rebounds and eight assists, but that performance is rightfully overshadowed in the loss.

3. Hey, just like that, Allonzo Trier is eligible

The news surrounding Arizona's most valuable player came in a hurry this week. Mysteriously, Trier was sat all through November and December, and then for the first two weeks of January. The reason? Well, many in college basketball media circles knew, but it couldn't be verified. Now we know: Trier accidentally ingested a performance-enhancing drug. He appealed to the NCAA, and won. This news came out only a couple of days ago. Then the unknown element: When would the PED leave his system?

Well, a test at the end of the week allowed for Trier to play on Saturday. His inclusion mattered. Arizona looked confident. Trier looked good. He played a lot more than I was expecting him to, coming off the bench but logging 27 minutes, scoring 12, grabbing seven rebounds and assisting on four baskets. If you're an Arizona fan, it's really a game-changer because you know that Trier is only going to get better as he gets more burn.

Speaking of Arizona's outlook ...

4. Yes, Arizona can have Final Four aspirations now

On my son's life, I swear to you I was going to pick Arizona in the preseason as a Final Four sleeper-type. But then the Wildcats lost Ray Smith for the season, and we weren't sure if Trier was going to be on the floor. So I bailed on the pick. And now I'm kind of regretting it. Check those video highlights again up top. Freshmen Lauri Markkanen and Kobi Simmons went off on UCLA. It's the best I think I've ever seen Simmons play, and that includes many games at the AAU level. He finished with 20 points, six rebounds, five assists and two steals. His game had verve to it on Saturday.

Markkanen was my preseason pick for Pac-12 Freshman of the Year, and with Ball and Markelle Fultz in the league, that's not going to happen, but man oh man did Markkanen eat T.J. Leaf for lunch. The 7-foot freak from Finland had 18 points and seven rebounds, was 3-of-4 from deep and held Leaf to 12 points and three rebounds on 5-of-10 shooting. He made himself some cheddar toay.

Combo those two with Trier, add in the vital play of glue-guy supreme Kadeem Allen, mix in another 7-footer with diversity (Dusan Ristic) and don't forget Rawle Alkins' athleticism, and yeah, Arizona's an 18-2 team with hopes on a great seed and dreams of getting to play in the Final Four where? Right in their backyard. Phoenix is hosting the event this year. Here's Allen getting his fun on.

5. What an environment in Pauley

Before we get out of here, I've got to give it to the UCLA home crowd. This was a great watch on CBS today. Loud, filled with dramatic moments, big shots, hustle plays. Dudes on the floor. The fan base was engaged. That building doesn't always sell out, but get hated Arizona in there on a Saturday afternoon, both teams ranked and fighting for a league race? Yeah, it was terrific. UCLA should get a few more fun ones like that before the season's over, but only Oregon would seem to be the team that will threaten to walk out of Pauley Pavilion with a W. UCLA is still one of the 10 best teams in America, even though it might wind up as the third-best team in the Pac-12.