CLEVELAND -- They only dressed eight and some of them left the court cramping up. Yet somehow, the Memphis Grizzlies found a way to stun the best team in the Eastern Conference.

Tony Allen returned from a knee injury to score a season-high 26 points, his most productive scoring night in five years, and the short-handed Grizzlies upset the Cleveland Cavaliers for a 106-103 victory Monday night.

"It's a happy locker room," Grizzlies coach Dave Joerger said. "Maybe one of the bigger wins I've had in my NBA career or in the nine years I've been with the Grizzlies."

Memphis was without five rotation players, including their three best: Marc Gasol, Mike Conley and Zach Randolph. Those missing combine for more than 49 points from their rotation, yet they still managed to beat the best team in the East. The Cavs committed a season-high 25 turnovers and didn't seem to fully engage until the fourth quarter.

"We could have done a better job of respecting the game," Kevin Love said. "That was a real bad loss for us."

Cleveland's Kyrie Irving had a chance to force overtime, but his 3-pointer at the buzzer bounced off the back of the rim. Irving scored 27 points, including 14 in the fourth period, and gave the Cavs their first lead with 2:39 remaining.

The teams traded the lead four times in the final 2:38, but the Grizzlies escaped when Allen tied up LeBron James, then won the tip on a crucial jump ball in the final minute when the ball drifted toward Allen.

"I had no chance," James said of the jump ball.

James finished with 28 points, nine rebounds and five assists, and Love had 14 points and 11 rebounds for Cleveland. Love shot 10 of 10 from the free-throw line.

The Cavs matched their previous season high for turnovers in a game (21) through three quarters. They fumbled away passes, skipped errant passes to where no one was standing and generally played with little court awareness.

"I don't care who you're playing," James said. "It could be my son's little league team and you're going to lose when you give up that many turnovers just from carelessness."

The Grizzlies seemed to catch the Cavs off guard by announcing Conley and Randolph were out an hour before the game. Irving said he spent the last day-and-a-half watching film on Conley and the team's game plan at the morning shootaround had been built around Randolph and Conley.

"Then we come in and the whole thing changes," Irving said. "We just have to get better as a team preparing for anybody that is out there on the floor, myself included. Caught me off guard a little bit. No excuses. We should have gotten this win tonight."

JaMychal Green had 16 points and 10 rebounds for the Grizzlies, while Mario Chalmers had 17 points and seven assists starting in place of Conley. Lance Stephenson scored 17 points off the bench, and reserve Vince Carter added 15 for Memphis, which had lost its previous three meetings with the Cavs. The Grizzlies lost their home opener to Cleveland this season by 30.

"This is big time for us," Carter said. "We had a lot of guys down. We told the young guys they were going to play a lot of minutes and just play hard. When you see shots go down you gain confidence."

The Grizzlies played at a faster pace than usual given all of the Cavs' turnovers. They shot 62 percent in the first quarter, led by 12 in the first half and as many as 14 in the third quarter before the Cavs rallied.

The Grizzlies still led 95-85 with 6:19 left when the Cavs made their final charge.

"I thought we kind of caught them off guard in the first quarter," Allen said, "and from that point on we felt good about ourselves and were confident throughout the game. … When you've got all the guys and they believe, the sky is the limit."

NOTES: Grizzlies G Mike Conley (foot) and F/C Chris Andersen (shoulder) are also expected to miss Wednesday's game at Boston. "We'll look at them more at the end of the week," Grizzlies coach Dave Joerger said. "They are going to be out for a while." ... Allen hadn't scored at least 26 points in a game since he scored 26 in a loss at Denver on Feb. 22, 2011. Allen returned after missing the previous eight games with a knee injury. ... Cleveland F LeBron James followed up his player of the month award for February by winning the player of the week award for the first week in March. ... James also passed John Havlicek for 13th place on the NBA's all-time scoring list. James now has 26,406 career points. ... James on UFC fighter Conor McGregor's upset loss Saturday to Nate Diaz: "Champions take lumps all the time. It doesn't make you less of a man. It doesn't make you less of a champion because you taken an L. ... We always get caught up in wins and losses. He will be a champion for the rest of his life and no one can take it away from him."