Alabama coach Nate Oats tried to warn his team.

Sure, Oklahoma would be without leading scorer Austin Reaves and starting guard Alondes Williams because of COVID-19 protocols. But Oats told his players that the Sooners still would be a problem for the Crimson Tide.

His players didn't listen, and they paid for it. De'Vion Harmon scored 18 points to help No. 24 Oklahoma defeat No. 9 Alabama 66-61 on Saturday in the SEC/Big 12 Challenge.

"Sometimes, when teams are down a couple of players there’s a galvanizing effect," Oats said. "It’s happened for us and against us. I thought these guys (Oklahoma), they play hard to begin with, and then when they’re down two starters, they really bought in. We tried to tell our guys. I’ve got to do a better job making sure we’re ready to play."

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Elijah Harkless scored 14 points and Brady Manek added 12 for the Sooners (11-4), who became the second team in the past 25 years to beat three top 10 teams in a row following wins over Kansas and Texas.

It also was the fourth victory for Oklahoma against a Top 10 team in the month of January. It was a critical win for the Sooners in a season that hasn't offered many opportunities for marquee non-conference games.

"It’s huge," Oklahoma coach Lon Kruger said. "Anytime you can win a game like that is big from a resume standpoint, big from a confidence standpoint, momentum. It’s continuing to move in the right direction. Those wins, you never take those for granted."

Alex Reese scored 15 points and Jaden Shackelford added 14 for Alabama (14-4), which saw its 10-game win streak end.

"Not our best performance," Oats said. "I told our guys if we can learn from it, it’ll end up helping us in the long run. We can go one of two ways. We can come back and play a lot better the next game or we could tailspin. We’ll see what our leadership does."

The Sooners forced six turnovers in the first five minutes and rolled to an 11-2 lead. The Crimson Tide rallied and tied the game at 17, and a 3-pointer by John Petty Jr. finally put the Crimson Tide ahead. Oklahoma rallied to take a 32-29 lead at halftime. Harmon scored 11 points before the break.

Jalen Hill's one-handed stuff down the middle of the lane put Oklahoma up 37-34 early in the second half.

Manek struggled with his shot before he scored in close and was fouled. His free throw put the Sooners up 47-40. Manek followed with a 3 to put Oklahoma up 50-41 with just under 12 minutes remaining. The Sooners pushed their lead to 12 points before the Crimson Tide rallied. A pair of free throws by Keon Ellis gave Alabama a 60-59 lead with just under four minutes to play.

Oklahoma responded again. With a 63-61 lead in the final minute, the Sooners worked the shot clock down before Harkless hit a difficult turnaround in the lane to push the lead to four with 19 seconds remaining and put Oklahoma in control for good.

"It was great," Kruger said of Harkless' shot. "It wasn’t picture by the book, necessarily. He had to kinda pivot a couple of times. The toughness to hang in there and get it off — it was huge. Huge play by E.J., and credit to him. Then we got a stop on the other end, and that was important as well."

POLL IMPLICATIONS

Oklahoma could surge near the Top 10. Alabama could take a significant hit with this loss, especially given the players Oklahoma was missing.

BIG PICTURE

Alabama: The Crimson Tide needed this one. Because the SEC doesn't have many ranked teams, Alabama has few opportunities to prove itself against top competition.

Oklahoma: The Sooners did the Big 12 a favor with a massive non-conference win that helps justify so many teams in the conference being highly ranked.

SOONER EMPATHY

Manek, who still is just getting back to normal after being out with COVID-19, said he feels badly for Reaves and Williams.

"Just got to make sure their mind’s right," Manek said. "It takes a toll on you, sitting at home watching guys you practice with every single day. It’s not fun. It sucks, honestly. Wish they were here, wish they could’ve experienced that. It was a big-time game and got a couple more ahead. We need them back."

QUOTABLE

Oats on Harmon: "I was out watching our guys warm up early and he was there full sweat, ready to play. I tell the kids ‘He’s amped up.’ They knew they were going to be missing their starting point guard. They pushed him over to it, and he did an unbelievable job."

STAT LINES

Harmon is averaging 18.2 points per game during Oklahoma’s five-game win streak while shooting 53% from the field.

UP NEXT:

Alabama: Hosts LSU on Wednesday.

Oklahoma: Visits No. 10 Texas Tech on Monday. The Sooners lost to the Red Raiders, 69-67, in Norman on Dec. 22.