Bradley Beal battles Heat guard Goran Dragic for a loose ball during the Wizards’ win in Miami on Saturday night. (Wilfredo Lee/Associated Press)

The strangest sight unfolded on the American Airlines Arena court. There was John Wall scowling, pounding his chest and pumping his fists, overwhelmed by celebratory emotions . . . in the fourth quarter.

Through the Washington Wizards’ lethargic start to the season, the team has underperformed and been one of the worst fourth-quarter teams in the NBA.

The end of games has been for moments of disillusionment, not displays of positivity. But on Saturday night, the Wizards finally showed up when it matters most and, behind a strong showing in the final quarter, posted a 116-110 victory over the Miami Heat.

“It doesn’t matter. The last five minutes of the game, you just got to fight through it. There’s no fatigue,” Wall said. “You work hard all summer . . . to prepare yourself for those type of moments. I just think we did a great job defending.”

While Wall, who confidently drilled a deep three-pointer and enthusiastically observed the 109-95 lead that it produced, found his jump-shooting rhythm, several of the newest Wizards discovered their ­purpose on the roster.

Austin Rivers attacked and clawed out of a slump. Dwight Howard concentrated on rebounding. And Jeff Green made almost everything in sight while playing virtually the entire second half in place of Markieff Morris.

Their efforts — combined with Otto Porter Jr.’s strong floor game and Bradley Beal’s offense sprinkled in while playing through foul trouble — produced a 33-point fourth quarter and temporarily stopped the bleeding for Washington, which improved to 3-9. The Wizards return home to host Orlando on Monday night.

Wall logged more than 41 minutes for the second straight night, and he finished with 28 points and nine assists. Beal added 18 points. Howard pulled down 16 rebounds to go with 11 points, and Green made his first seven shots and finished with 19 points. Porter scored just seven but contributed steady perimeter defense.

“It’s the best one, by far,” Beal said of the team’s defensive performance.

Before the Wizards completed their first back-to-back set of the season, Coach Scott Brooks confirmed that his starting lineup would not change. However, he hinted at other revisions.

“When you’re 2-9, everything [is on the table],” he said. “We tried to change some of the rotations the last couple of games. Taking guys out, putting guys back in sooner than they’d normally be put in . . . just trying things to generate some good combinations, whether you’re starting or coming off the bench.”

On Saturday night, Brooks returned to backup center Ian Mahinmi, who had not played in the previous three games, but he remained constant in using an all-bench lineup. In the past when the Wizards went with the complete second unit, small deficits turned into giant holes. But the group inherited a 10-point deficit at the start of the second quarter against the Heat on Saturday and found a way to keep the Wizards in striking distance.

“I think defensively we stuck with it. Managed to stay in the game when they made their runs. They made their runs; we kept our composure,” Green said. “We continued to play together. I think that was big time for us.”

After Kelly Oubre Jr. smothered Heat forward Kelly Olynyk for a steal, Rivers drove for a reverse transition layup and pulled Washington within 45-40 with 6:48 remaining. Rivers created offense mostly on his own by consistently attacking the rim; he finished with a season-high 18 points on 7-for-12 shooting.

By the time the starters returned to the court later in the quarter, they didn’t have to waste energy trying to recover from a double-digit deficit. Instead, with focused aggression on both ends, the Wizards pulled even closer by halftime and trailed only 61-58.

Washington squeaked by the Heat 25-24 in the third quarter but took over in the fourth. Entering the matchup, Washington ranked 26th in the NBA in fourth-quarter point differential (minus-2.4). That changed Saturday night: The Wizards outscored the Heat by eight.

“We needed this one — no other way to put it. This is a game that we had to have,” Green said. “I think that we fought through it, and we battled for it. That’s all you can ask for.”