Oregon kept its composure in one of college basketball's toughest road arenas, leading No. 2 Arizona well into the second half.
Once the Wildcats turned up the pressure and the fans inside McKale Center turned up the noise, the Ducks had no answer.
Ahead for most of the second half, Oregon faded down the stretch with key turnovers and three missed free throws in a 67-65 loss Thursday night.
"We've got to make better decisions and better plays," Oregon coach Dana Altman said. "We didn't execute. That's as much my fault as theirs."
Coming off its first loss of the season, Arizona (22-1, 9-1 Pac-12) labored offensively in its first game without forward Brandon Ashley, who is out for the season with a foot injury suffered last Saturday in a loss at California.
The Wildcats went 4 for 16 from 3-point range, missed 16 free throws and had a tough time even getting into their set plays.
They turned up the pressure with the game on the line and, as they also have for much of the season, found a way to make the big plays when they needed to.
Point guard T.J. McConnell missed seven of his first eight shots before dropping in a 3-pointer with 90 seconds left to give Arizona the lead.
Nick Johnson went 5 of 16 from the field, but kept fighting his way through it and hit 5 of 6 free throws in the final 47 seconds to finish with 18 points.
Rondae Hollis-Jefferson provided the Wildcats with a big lift, too, finishing with 14 points, 10 rebounds and all kinds of not-in-the-box score contributions with his hustle in his first start in place of Ashley.
"Our offense was a little out synch play-wise, but we battled back," McConnell said. "We've done that so many times this year, been in games like that before, so I think we're a battle-tested team."
Oregon (15-7, 3-7) has been through a few battles of its own, but has been on the losing end lately.
The Ducks had two turnovers late and missed 3 of 4 free throws in the final 23 seconds for another oh-so-close loss.
Joseph Young and Jason Calliste had 14 points each and Damyean Dotson added 12 for Oregon.
"They're hurting," Altman said. "This is their third two-point loss. I just told them we've got to be resilient. It hurts having an opportunity and not being able to finish."
Arizona had to shuffle its lineup with Ashley out, moving Hollis-Jefferson into the starting lineup and long-range shooter Gabe York into his sixth-man role.
The new-look rotation was solid early, dropping in 3-pointers and flying in for dunks while Kaleb Tarczewski had his way inside for 10 points and five offensive rebounds.
After that, it was a struggle.
With the Ducks double-teaming Tarczewski in the post and McConnell out with his third foul late in the first half, Arizona could only find an offensive rhythm in stretches. The Wildcats didn't help themselves at the free-throw line, either, making 11 of 19 in the first half.
Arizona got off to a slow start in the second half and trailed most of the way as the shots continued to bounce away.
The Wildcats have proven to be strong-minded most of the season — their only loss was on a last-second shot by Cal — and again found a way to pull out a not-so-pretty victory.
"Tonight's game is a real tribute to the team that we have in that it took a lot of resiliency on our part, a lot of belief and toughness because things weren't going our way," Arizona coach Sean Miller said.
Oregon, the defending Pac-12 tournament champion, has been in a downward spiral since conference play started, losing five straight after being ranked as high as 10th. The Ducks bounced back with two wins in their previous three games, but still needed to start winning to have a chance at returning to the NCAA tournament.
Oregon got off to a slow start against Arizona, but started dropping in shots to lead 38-37 at halftime.
The Ducks pushed the lead to seven points midway through the second half, but faltered down the stretch.
Oregon fell behind by four after a shot-clock violation and a wild 3-point attempt by Young, yet still had a chance in the closing seconds.
The Ducks pulled within 64-62 on Dominic Artis' shot in the lane, but he missed two free throws and Calliste hit 1 of 2 as Arizona's fans waved wildly in the background.
"I thought we were in pretty good shape, but didn't finish it," Altman said.