CORVALLIS, Ore. (AP) Allonzo Trier said he's excited to be playing basketball again with his Arizona teammates after missing the first 19 games of the season. He's still a long way from feeling like himself on the court, both on offense and defense.

''It's still a step slow. I'm still out of rhythm. I'm still not shooting the ball great,'' the sophomore guard said. ''I'll be better. I know that.''

And that should be a scary thought for Pac-12 opponents.

Trier scored 18 points and No. 5 Arizona roared to life in the second half to defeat Oregon State 71-54 on Thursday night.

Dusan Ristic had 10 points and six rebounds for the Wildcats (21-2, 10-0), who have won 15 straight games.

Stephen Thompson Jr. had 16 points and five steals and Drew Eubanks added 12 points for the Beavers (4-19, 0-10).

Arizona went on a 23-2 run in the second half to take a 55-36 lead with 8:23 remaining. The Wildcats held the Beavers scoreless for nearly 6 minutes during the surge.

Trier credited a focus on defensive details for the second half turnaround.

Arizona coach Sean Miller said that defensive stops made it easier to push the tempo in the second half.

''Our defense led to some good transition baskets,'' he added.

Arizona led by eight points early, but Oregon State battled back and went ahead 23-21 after a 3-pointer by Thompson with 4:53 left in the first half.

The Beavers lead 29-27 at halftime.

Oregon State shot 50 percent in the first half, but was limited to 34.6 percent in the second half. Arizona shot 53.8 percent in the second half and outrebounded the Beavers 39-26 for the game.

Oregon State coach Wayne Tinkle said that his young squad lost its composure.

''Once a little frustration creeps in, we're just not there yet maturity-wise, toughness-wise, to get it back,'' he said.

BIG PICTURE

Arizona: The Wildcats' last loss came Dec. 2 to now No. 1 Gonzaga. ... Trier was cleared to play this season on Jan. 21 after being suspended for use of PEDs, and in his first three games he averaged 13.7 points, 5.7 rebounds and 4.7 assists. ... Lauri Markannen, Arizona's leading scorer, shot 1 for 6 from the field but finished with eight points and nine rebounds.

Oregon State: Leading scorer Tres Tinkle, who last played Nov. 25, remains out indefinitely with a wrist injury. ... Eubanks' streak of 17 games with a block ended Thursday.

OREGON PAYBACK?

Trier said Arizona has a different squad than the team that had its 49-game home winning streak snapped against Oregon last season. But the Wildcats don't need any extra motivation for Saturday's game against the 13th-ranked Ducks.

''We know how good Oregon is,'' Trier said. ''It's going to be a hard-fought game and we're excited for the challenge.''

ZONA AND THE ZONE

Miller said the Wildcats moved the ball well against Oregon State's zone defense early in the first half, but then open shots didn't fall and players tried to solve things 1-on-1.

''It started to become more about, `Hey, let me make one myself and see if I can get out of this rut.' When you do that against the zone, it's never going to be quite good,'' Miller said.

POLL IMPLICATIONS

Thursday's game likely had minimal poll implications, but Arizona's matchup with Oregon on Saturday will be closely watched.

UP NEXT

Arizona plays at No. 13 Oregon on Saturday.

Oregon State hosts Arizona State on Saturday.

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