John Wall scores against Boston’s Al Horford as the Wizards roll to their 14th straight win at home. (John McDonnell/The Washington Post)

Bradley Beal had the brainstorm. The Washington Wizards should dress in all black Tuesday in preparation for their budding rivalry game against the Boston Celtics.

It seemed a brazen idea from someone who had only recently snapped the worst three-point shooting slump of his career and played through the lingering effects of a sore left foot. But Beal showed up wearing a black Balmain coat, then backed up his fashion statement on the court with a game-high 31 points in a 123-108 win at Verizon Center.

“It is hoops, man. People talk. Nobody came in today expecting a fire or anything like that. We came out and played good basketball on both sides,” Beal said. “There [were] no dirty plays. It got a little chippy here and there, but that is part of the game. That is a playoff-type atmosphere. That is a team that is going to be in the playoffs and who is going to be a tough team to beat down the line, so we just came in and made sure we were locked in and ready to go from the get go.”

Beal, who made 12 of 18 shots from the field, was one of the starters who finished the game on the bench. He wildly waved a blue towel, then chest-bumped backcourt partner John Wall, and together they celebrated their league-best home streak of 14 straight wins.

Wall finished with 27 points, seven rebounds and seven assists , while Markieff Morris contributed 19 points and 11 rebounds .

The Wizards (25-20) have won two of the three regular season meetings against the Celtics. Though previous matchups had produced on- and off-court confrontations, the Wizards found a new way to beat this foe — just by shutting up and playing.

“We want to conduct ourselves in a professional manner. It’s a competition, but you want to keep it between the lines,” Coach Scott Brooks said. “We kept it between the lines, we competed, we moved on to the next game.”

Behind the bold statement to wear black — a unifying trick usually reserved for playoff games — the Wizards gave themselves little margin for error. Washington, fresh off a win in Charlotte on Monday night, came in with just a 2-7 record in the second of back-to-back games. In contrast, Boston, eager to break a two-game losing streak, had been resting since Saturday night.

Everything that had worked through the streak — the repetitive hum of success since Dec. 8 — surely was disrupted the moment players arrived at Verizon Center. At no other time this season had they faced a horde of cellphones and cameras to document the clothes on their backs as they walked in like runway models.

However, the Wizards simply shot down the diversion. The team made 57.8 percent of its shots while defending Boston into 23 misses from the three-point arc and 45.2 percent shooting overall.

“We knew it was a lot of pressure because we said it was the all-black game. [There] was added pressure,” Wall admitted, “but we just looked at it as another game on the schedule but we knew it was a big game. We passed it now.”

Players expected trash-talking and physical play, and so did the officiating crew. In the first half, 14 personal fouls stopped the game. And in the third quarter, Morris picked up a technical foul during a free throw line skirmish with Jae Crowder.

But between the incessant whistles, the Wizards played a basketball game — and a well-executed one at that.

On Monday in Charlotte, the Wizards’ offense shined, connecting on 53.8 percent from the field. They were even hotter in first half against the Celtics, shooting 65 percent overall, including 8 of 13 from three-point territory. Before halftime, Marcin Gortat connected on his five close-range attempts, Otto Porter Jr. didn’t miss from beyond the arc (2 for 2), and four starters reached double figures .

Continuing the trend, the Wizards’ backcourt led this proficiency. Beal kept his teammates engaged — assisting on two early field goals while the Wizards made their first six shot attempts — while also warming up for his own offense. Beal found many of his jump shot opportunities from his aggression in one-on-ones and went into intermission with 14 points to go with five assists.

Wall was just as effective, stepping up whenever Washington needed energy.

After Boston pulled within 26-24, Wall closed the first quarter with consecutive jumpers. Later, Wall gave the Wizards the 66-59 halftime lead by taking on Boston’s Al Horford in the closing seconds and beating the 6-foot-10 center to the rim. Then late in the third, Wall came up with a steal and set off in a footrace against Marcus Smart. Undeterred by imminent contact, Wall fearlessly attacked the rim. After his underhanded layup ripped the net, Wall heard the whistle for the foul and flexed his right biceps to the crowd.

Even Beal, the quiet one in the duo, could not contain his emotions. In the fourth quarter, Beal erupted for 13 points on 6-for-7 shooting. He all but ended the Celtics with a crossover move against Smart and finish at the rim with 3:58 remaining. After the bucket, Beal lowered his head, glowering and shouting in Smart’s direction. At that point, the men in black had buried the Celtics.

Players maintained the all-black night was meant in good fun, and if anyone transgressed the memo he would have to get his head shaved. However after the impressive win, Washington may want to seriously consider more dress codes.

“If that’s what y’all want, we’ll give it to y’all,” Morris said. “We’ll wear all white next game.”