KNOXVILLE -- Isabelle Harrison wasn't looking for an extended workout, but the Tennessee center got it all the same.
Harrison tied her career high with 35 minutes and finished with 20 points, 12 rebounds and five blocks Sunday in leading No. 8 Tennessee past No. 10 Oregon State 74-63.
"I haven't played that many minutes since last year," Harrison said with a laugh. "You know, I got my cardio for sure today. It helped, but I just have to get used to that many minutes."
Freshman Alexa Middleton added 12 points off the bench, and the Lady Vols (10-2) handed the Beavers (10-1) their first loss.
Tennessee has now defeated two straight top-10 opponents. The Lady Vols beat Stanford 59-40 on Dec. 20.
Guard Sydney Wiese led Oregon State with 19 points on 6-for-17 shooting. Ali Gibson added 14 points -- 12 in the second half.
Middleton scored six consecutive points midway through the second half, and her jumper from the top of the key with 8:10 to play gave the Lady Vols a 56-52 lead. She hit five of her six shots.
"I've just been making a point (during practice) to get up extra shots," Middleton said. "We had a good practice yesterday. I guess that carried over."
Tennessee maintained a seven-point cushion down the stretch at the foul line, though the Lady Vols made just 22 of 34 free throws overall. Oregon State went to the line only nine times and made seven.
The Beavers didn't make a field goal the final 3:37 and failed to score the final 1:47. They missed all seven 3-pointers after the break, having made 6 of 9 in the first half. Tennessee trailed late in the first half but scored the final six points to go up 35-34.
"That's a huge win for us," Tennessee coach Holly Warlick said. "They're just a difficult team to play. They shoot the 3 and penetrate. Someone asked me if they should be in the top 10. No question."
Wiese entered the game shooting 52 percent from the 3-point line and made her first three 3s Sunday. She wound up 3-for-7 from behind the arc.
Tennessee scored 26 points off 19 Oregon State turnovers.
"They have the ability to pressure more than most teams," Oregon State coach Scott Rueck said. "That's how they survive and live. They thrive off that."