FAYETTEVILLE, Ark. — Marshawn Powell still won’t say he’s 100 percent healthy after last year’s knee surgery that kept him out for most of the season.

The Arkansas junior — who says he’s 95 percent — looked every bit his old self on Tuesday night, scoring a career-high 33 points to help the Razorbacks avoid a three-game losing streak with an 81-78 win over Oklahoma.

Powell added six rebounds and five assists for Arkansas (4-3), which avoided its first four-game losing streak since closing out the 2009-10 season with six straight losses. The forward bested his previous career high of 29 points, which was set against Appalachian State in 2009.

“I felt so comfortable today,” Powell said. “I decided before we started playing just to leave everything that was basically in the last couple of games in the locker room and just play, play my game, play how I play.”

The Sooners (6-2) rallied from an 11-point second-half deficit to take a 78-77 lead in the closing minute.

However, Arkansas’ BJ Young answered with a floater in the lane to put the Razorbacks back up 79-77 — a lead they held on to for good.

Romero Osby led the Sooners with 22 points, while Amath M’Baye finished with 14 and Steven Pledger 12. Oklahoma was 31 of 56 (55 percent) from the field, including 64 percent in the second half, but it struggled to stop Arkansas, which was 30 of 57 (52.6 percent) from the field.

“We had good movement, attacked and made plays for each other, had rhythm jumpers,” Oklahoma coach Lon Kruger said. “I though the offensive side of it wasn’t our problem there in the second half. We gave up 50-plus percent shooting as well.”

Arkansas, which led all except in the early going, led by as many as 11 points early in the second half — taking a 53-42 lead after a basket on the break by Hunter Mickelson.

Oklahoma rallied and took a 78-77 lead in the closing minute after a second straight 3-pointer by Pledger with 22 seconds remaining.

Young, however, quickly drove into the lane on the other end for the Razorbacks and hit his running floater to put them back up 79-78 with 15 seconds remaining.

“It was just time for a big-time player to make a big-time play,” Young said.

Osby then missed a long jumper with 4 seconds remaining, and Powell grabbed the rebound for Arkansas. He was fouled and then hit two free throws with 2.4 seconds left, and he followed that up with a deflection to keep the Sooners from getting an open look as time expired.

“I thought it was going in when it left my hand,” Osby said. “Unfortunately, it didn’t.”

Powell missed all but two games last season with a torn ACL in his right knee, one year after earning second-team All-Southeastern Conference honors. He entered the game averaging 13.3 points per game this season, including a 19-point effort in a loss last week to Syracuse.

The 6-foot-7 forward had that many points by halftime against Oklahoma, helping Arkansas extend its lead to as many as nine points in the first half. His layup put the Razorbacks up 31-22, and he was 7 of 9 from the field in the half, including a perfect 3 of 3 on 3-pointers.

He finished a career-best 4 of 6 from behind the arc, topping his previous best of two 3-pointers in a game.

“It was good to see him really look in rhythm, but not only on just offense, but I thought defensively,” Arkansas coach Mike Anderson said. “I thought his presence was very, very important for our basketball team out there. It was very evident tonight.”

Young also finished in double figures with 10 points, as did Mardracus Wade for Arkansas, which was 9 of 22 on 3-pointers. Young also had eight assists.

The Razorbacks led 69-61 after an inside basket by Ky Madden, but Oklahoma closed to within 69-68 thanks to a 7-0 run that was capped by a jumper by M’Baye.

Arkansas used a pair of last-second shots to hold off the Sooners down the stretch. The Razorbacks were called for a shot-clock violation while up 73-68, and Oklahoma closed to within 73-70 after an inside basket by Osby.

With the shot clock once again winding down, Madden found Powell for a jumper on the baseline that put Arkansas back up 75-70.