A.J. Price returned to the Wizards’ lineup in time to celebrate Bradley Beal’s game-winner over the Thunder. (Alex Brandon/Associated Press)

When the Washington Wizards stepped on the floor on Monday night against the Oklahoma City Thunder, Coach Randy Wittman had to ask two injured players to come back a little earlier than expected to help a short-handed team that was all alone in the NBA basement with four victories — half as many wins as the next-worst team in the league.

When they left the floor, euphorically celebrating an improbable 101-99 victory and rookie guard Bradley Beal’s first career game-winning jumper, the Wizards (5-28) suddenly became the second occupant of an exclusive NBA club.

The Memphis Grizzlies, owners of the fifth-best record in the league, were the first team this season to claim wins against last year’s NBA finalists — the defending champion Miami Heat and Western Conference champion Thunder. Now the Wizards can make the same claim, with two of their five victories coming against the NBA’s elite.

“We just fight. You know, we play,” center Emeka Okafor said, when asked to explain the confusing development. “I don’t think our record is reflective of what we are capable of doing. Throughout the season, I don’t know for one reason or another, things haven’t gone our way. But the wins that we have and who we played against, shows that we’re a team of fighters. We don’t give up.”

The Wizards are now 2-2 against the Thunder and Heat and 3-26 against the rest of the NBA.

“That’s something that you can’t explain,” said forward Trevor Ariza, who returned from a 17-game absence because of a strained left calf suffered in the win against Miami on Dec. 4. “But we came out and played hard, played for each other. I always feel good about our chances, no matter who we have out there. We work on our games every day. We’re professionals.”

LeBron James dismissed the early loss to the Wizards, stating that teams usually bring their best against the champs and “they’re going to make shots that they normally don’t make.” Kevin Durant said the Thunder lost because “we aren’t taking it serious enough.”

Riding a five-game losing streak that included a double-overtime loss two days earlier to Brooklyn, in which they squandered an eight-point lead with 75 seconds remaining in overtime, the Wizards had the look of a defeated team when they arrived at Verizon Center a few hours before tip-off Monday.

Leading scorer Jordan Crawford was unable to go because of a sore left ankle. Nene, the team’s best low-post presence despite playing limited minutes because of a sore left foot, had to back out because of a new ailment, right knee tendinitis. And key reserve Cartier Martin couldn’t walk without the assistance of a brace after hyperextending his right knee in a loss on Sunday night in Miami, where the Heat scored the game’s final 21 points.

“Losing can become very discouraging,” point guard A.J. Price said.

Ariza and Price had recently started participating in full-contact practices and were eager to return, but with John Wall (left knee) and Trevor Booker (right knee) also out — and Wittman banishing Chris Singleton to the bench — the Wizards had just nine players available against the Thunder.

Aware of the controversysurrounding Redskins Coach Mike Shanahan’s decision to allow quarterback Robert Griffin III to play and aggravate a severe right knee injury during Sunday’s NFL playoff game, Wittman joked that he had “doctor’s approval” to play Ariza and Price, who had missed the previous 15 games with a broken right hand.

“He didn’t have to say anything to convince me,” said Ariza, who can now claim wins over the Heat and Thunder in his past two appearances with the Wizards. “They said I can play and I wanted to play. That’s the type of person I am, that’s the type of person A.J. is and anything to help the team try to get wins, that’s what we try to do.”

The Wizards defeated the defending champion Miami Heat and the runner-up Dallas Mavericks in 2006-07, when Gilbert Arenas and Caron Butler made the all-star team and Eddie Jordan was the coach.

Six years later, they have finally done it again as what is shaping up to be a historically bad team.

The Wizards, who were 1-13 when they beat Miami, are now just the second team in NBA history with a winning percentage worse than .200 when it defeated the previous NBA finalists. The 13-win Atlanta Hawks defeated the defending champion Detroit Pistons and the Los Angeles Lakers in 2004-05.

After defeating Miami, the Wizards went on to lose 10 of their next 11 games, but they feel more encouraged about being able to build on their latest victory over Oklahoma City. Plus, Wizards owner Ted Leonsis hinted on his personal blog that Wall could make his season debut on Saturday against Atlanta after being sidelined since late September with a stress injury in left knee.

“We’re not going to hang our heads low,” Okafor said. “We have fans that are rooting for us. We go out there to win.”