The visiting locker room at US Airways Center was filled with the usual laughter and playful banter that comes following a victory, but the Washington Wizards’ celebration of a much-needed road win over the Phoenix Suns was tempered some by what was happening behind a glass window leading to the training room. There, rookie Bradley Beal sat with a white towel covering his head, left leg elevated as he received treatment on a troublesome ankle that he aggravated in the fourth quarter of the Wizards’ 88-79 win.

“It’s tough for him,” forward Trevor Ariza said, looking back at the beleaguered Beal. “I feel bad for him that he has to go through this.”

Beal will likely miss more time after his second gruesome landing this month; the latest coming during a near meltdown in which the Wizards let an 18-point lead get whittled down to just three points with about nine minutes remaining.

But John Wall refused to let the Wizards waste the valuable contributions of reserves Kevin Seraphin and Ariza, the gutty play of Nene or even the valiant effort of seldom-used backup Jason Collins, who was thrust into the starting lineup when Emeka Okafor was forced to sit with the flu.

More importantly, Wall stepped up as he did the last time Beal crumpled to the ground and needed assistance to the locker room, scoring six points and had two assists in the fourth quarter as the Wizards snapped a five-game road losing streak and also ended a five-game skid in Phoenix, where the franchise hadn’t won since Dec. 22, 2006.

“I have a lot of confidence in myself right now,” Wall said after finishing with a game-high 19 points and eight assists and helping the Wizards improve to 19-15 since he returned from a stress injury in his left knee on Jan. 12 — the sixth-best mark in the Eastern Conference during that span. “It’s tough to always talk about, but I feel this is easily a playoff team. Easy. But it’s so much going on and God makes things happen for a reason. We’re dealing with this right now, for better success up the road, but that’s all I can look at it as.”

By winning on the road for just the sixth time in 32 tries, the Wizards (24-43) secured their most wins since drafting Wall first overall in 2010. They also swept their third Western Conference opponent this season, after doing the same against Portland and Denver, and captured the season series against Phoenix for the first time since 2001-02 — and for just the second time in the past 25 years.

The Wizards had it relatively easy through the first three quarters, with Seraphin (16 points) and Ariza (14 points) combining for 26 points during a game-changing 31-6 first-half run augmented by a stout defense. But after taking a 50-32 lead in the second quarter and holding a 17-point lead in the third period, the Wizards suddenly fell complacent and let the Suns creep back into the game with sloppy and careless errors.

And then, as they were sleepwalking toward the finish, the Wizards had to deal with some serious adversity when they lost Beal.

Beal missed six games this month with a sprained left ankle, but had been playing through the pain since returning against Phoenix four days before. He tweaked the ankle in the second half of the Wizards’ loss in Charlotte to start this four-game road trip on Monday, but he hurt himself even more with 9 minutes 53 seconds left in the fourth quarter.

Suns guard Shannon Brown stole the ball from Beal and he gave chase, but after leaping to contest the layup, Beal landed awkwardly and immediately covered his face and twisted in agony. Needing assistance to stand, Beal was assessed a technical foul before leaving the game for good.

“It’s very sad to see your back court mate go down,” Wall said of Beal, who finished with just six points in 19 minutes. “Even when he came back, he was fighting, dealing with it.”

Shortly after Beal left, the Suns got within 75-72 when reserve big man Hamed Haddadi made a layup, but the Wizards responded by scoring seven straight points. Wall found Seraphin for a foul line jumper, then hit a 15-foot jumper of his own. And after Nene (17 points) made a free throw, Wall stole a pass from Suns point guard Goran Dragic and knocked down an 18-footer to push the lead back to double digits.

“Every time when we relax, the other team always steps up,” Nene said, reaching for his jaw, which remained sore after absorbing a hit from Suns forward Luis Scola. “We need to learn to control the game, control our advantage and trust in each other and read what the game was giving to us. We relax and they went on a run, but we stepped up in the last quarter.”

Okafor, the only player Coach Randy Wittman could pencil in for the Wizards’ first 66 games, came down with the flu and Wittman decided to start Collins at center for the first time. Collins had only appeared in one game since he was acquired at the trade deadline in exchange for Jordan Crawford, but Wittman decided to give the physical, defensive-minded player a chance to defend Suns center Jermaine O’Neal.

Collins didn’t score, but he made the night difficult for O’Neal, who scored 12 points but shot just 3 of 11 from the field. Collins also had two assists, feeding Martell Webster (13 points) for a three-pointer in the left corner late in the game.

The Wizards allowed the Suns to score 25 points off 21 turnovers but limited Phoenix to just 33.7 percent shooting. After thrashing the Suns, 127-105, in a shootout in their first meeting, the Wizards were able to win with a more familiar, grind-it-out style.

“Defensively, we won the game. Defensively, we got back to the team we recognize; scrambling, challenging shots, rebounding the ball,” Wittman said. “Yeah, we almost shot ourselves in the foot there. But I’m proud of our guys.”