It turns out Adem Bona cannot be everywhere all at once on defense for UCLA.

Trailing 60-59 and deploying a press defense, the sophomore forward chased an Oregon inbounds to Jackson Shelstad at the 3-point line as part of a double team and was too late to recover in time to defend a quick pass to Kwame Evans Jr. for an otherwise uncontested dunk with 25 seconds left.

Now down 62-59, Bruins guard Dylan Andrews was unable to duplicate his previous attempt and misfired on a 3-pointer with 15 seconds to play.

Shelstad then sank a pair of free throws to ice Oregon’s 64-59 win over UCLA Saturday afternoon at Matthew Knight Arena in Eugene, Ore.

UCLA (6-7, 1-1 Pac-12) shot an identical 12 of 28 from the field in both halves but was just 3 of 19 for the game on 3-point attempts. The Bruins also committed 16 turnovers.

“I told the guys, you know, if we take care of the ball, keep our turnovers down, we’re going to win,” UCLA head coach Mick Cronin told the Los Angeles Times after the game. “We didn’t do that. We didn’t control the game. We got loose and sloppy with the ball. That cost us the game.”

Bona finished with 15 points, 11 rebounds and five blocks to pace the Bruins, while freshman forward Berke Buyuktuncel added 12 points. The pair shot a combined 11 of 14 from the floor but were unable to consistently get touches for stretches.

“Frustrating, frustrating shot selection. We gotta get the ball inside,” Cronin said.

Oregon (10-3, 2-0 Pac-12), which was without leading scorer N’Faly Dante (knee) and fellow big man Nate Bittle (wrist), was able to overcome UCLA’s size advantage.

The Ducks made 10 3-pointers and were led by Shelstad’s 20 points. He connected on 7 of 13 shots from the floor, including 4 of 7 beyond the arc.

Courtesy of UCLA Athletics:

Freshman guard Sebastian Mack knocked down a pull-up jump shot in the closing seconds of the first half to pull UCLA with 33-31 at the break.

A 9-0 run early in the second half put the Bruins in front 42-37 with 15:08 to play.

Turnovers, however, helped Oregon remain close and back-to-back 3-pointers gave the Ducks a 43-42 lead.

Oregon stretched the advantage to 51-44 as UCLA continued to struggle with taking care of the ball.

Buyuktuncel then scored the next seven Bruins points, including a 3-pointer to spark the outburst, and Bona tacked on a layup to cut UCLA’s deficit to 55-53 with 5:21 remaining.

Mack, however, lost possession after an offensive rebound off a missed Bona free throw and the Ducks responded with a quick spurt of their own.

Shelstad took advantage with a transition 3-pointer, which was then followed by another Mack turnover and Jermaine Couisnard’s layup to quickly bump Oregon’s lead to 60-53.

“Sebastian went for a steal that started their run,” Cronin said.

UCLA’s defense then held Oregon scoreless for the next 4 minutes, 9 seconds to set the stage for the game’s final 30 seconds.

The freshman from Turkey had his best performance of his young career, scoring on a variety of moves in the post and with his jump shot.

Buyuktuncel helped complement Bona inside, giving the Bruins a much more fluid look on offense.

As a result, freshman center Aday Mara did not play.

It was another strong, stat-stuffing performance from Bona. It was again made possible by staying out of early foul trouble.

Even when we wasn’t blocking shots, Bona was altering them and picked his moments to stand his ground.

For starters, the Bruins guards Andrews and Lazar Stefanovic combined to shoot 6 of 26 from the field.

Stefanovic, the transfer from Utah who was brought in for his 3-point shooting, missed all six of his attempts from beyond the arc.

“I was disappointed at Lazar today,” Cronin said. “He’s a wonderful kid. His shot selection was disappointing.”

Mack’s turnovers and his own shot selection only compounded the issues. While he’s shown a knack for getting to the free-throw line early in his career, the combo guard did not shoot a free throw and he often had tunnel vision on his drives to the basket as opposed to keep an eye out for potential kick outs to open teammates on the perimeter.