DALLAS -- The Washington Wizards' enjoyed a 21-point lead late in third quarter and were up double digits late into the fourth Saturday night.

The fact that the Dallas Mavericks were within one shot in the final seconds didn't take away from eventual outcome.

"This was a good win," Wizards coach Randy Wittman said. "Don't spin it any other way. This was a gutty win for us."

Small forward Otto Porter racked up a career-best 28 points and point guard John Wall had another gem in the Wizards' 114-111 victory over Dallas at American Airlines Center.

The Wizards (10-12) snapped an 11-game losing streak to Dallas and won for only the second time on second half of a back-to-back this season.

Washington did so without shooting guard Bradley Beal, who's out for at least two weeks with a leg injury. Beal's absence mattered little with Porter coming through with the highest-scoring performance of his three-year career.

Porter was at his best in the third quarter as the Wizards turned a one-point game into a near rout. The Georgetown product knocked down 7 of 8 shots from the field and scored 17 points in the third alone.

Porter finished 11 of 18 from the floor, including 4 of 8 on 3-pointers. He grabbed six rebounds and doled out three assists. Porter's previous high was 23 points.

"He's just got to continue to shoot," Washington center Marcin Gortat said. "With all respect to Dirk (Nowitzki), Dirk was defending him like he couldn't shoot the ball. We told him to just keep shooting. If you're going to miss, keep shooting. I'm glad he used this opportunity to be aggressive and he had a great game."

Washington shot 51.8 percent from the field for the game and outscored Dallas 31-14 in fast-break points.

Wall extended his streak of scoring at least 26 points and delivering seven assists to a career-best five consecutive games. Wall had 26 points and a season-high 16 assists.

Gortat had his fifth double-double in the last six games with 14 points and 12 rebounds. Shooting guard Jared Dudley scored 13 points.

The Wizards began to pull away early in the third quarter, racing out to a 13-point lead behind Porter. Dallas coach Rick Carlisle called two timeouts in the first four minutes of the period, but it didn't slow down the Wizards.

Their shots kept falling even as Dallas began to find their offensive rhythm. A layup from Washington reserve point guard Ramon Sessions pushed the advantage to 90-69 late in the third quarter.

"They played better than us," Carlisle said. "They're relatively young and they have a lot of skilled guys out there. We allowed them to get into an unbelievable shot-making grove. It's a one-point game at halftime, which is manageable. The third quarter was what did us in."

Dallas backup point guard J.J. Barea (21 points) led a furious rally in the final minutes to get Dallas within a possession in the closing seconds. Barea made two free throws with 4.4 seconds left to make it 112-111.

Wall made two foul shots with 3.7 remaining before Nowitzki's 3-point try at the buzzer glanced off the front rim.

The Wizards lost 107-105 at New Orleans on Friday.

"Nobody has hung their head," Wittman said. "We've had guys step up and come in here and build a 21-point lead. We made a stop at the end that we needed to make.

"We didn't do that last night. We didn't get that stop that would have won the game. This was a good, gritty, gutty performance for our guys and I'm really proud of them."

The Mavericks (13-11) have dropped their first two games on a three-game homestand that ends Monday night against Phoenix. Dallas is now 5-5 at home after a third straight loss on its court.

"We need each other to get more juiced up to play here," Carlisle said. "We can help each other get better shots, we can help each other defend better. That kind of chemistry is going to be paramount to our success."

Nowitzki suffered through his second straight poor outing, making just 3 of 9 shots from the floor for 13 points. The Mavs' leading scorer was 6 of 20 in Wednesday's loss to Atlanta.

Shooting guard Wesley Matthews did his best to keep Dallas close. After drilling a career-high 10-pointers and scoring 36 in last Sunday's win at Washington, Matthews hit another six from deep and scored 28.

Point guard Raymond Felton, subbing for ailing Deron Williams, cobbled together a triple-double with 10 points, 11 rebounds and 11 assists.

The Wizards, 6-5 away, continue their four-game road trip Monday at Memphis.

NOTES: Wizards SG Bradley Beal is out for at least two weeks because of a stress reaction in his lower right fibula. The injury was initially diagnosed Friday and confirmed Saturday by the team. Beal, averaging a career-high 19.8 points, was scratched from Friday's loss at New Orleans. ... Mavericks PG Deron Williams (stomach illness) sat out. SF Chandler Parsons returned to the starting lineup. ... Dallas recalled rookie SG Justin Anderson from the D-League Texas Legends before the game. ... Dallas held its 11th annual Seats for Soldiers event, with courtside seats being donated by fans to wounded service members, veterans and reserve troops.