WASHINGTON -- With only one win in their opening 11 games, the Dallas Mavericks decided they were done playing the role of patsy.

After recent flops at home, the Washington Wizards claimed they were focused on tightening up their defense.

Turned out the underdog reached its goal.

Harrison Barnes scored 31 points as the Mavericks, owners of the NBA's worst record, upset the Wizards 113-99 on Tuesday night.

Dennis Smith Jr. had 22 points and Wesley Matthews 14 for the Mavericks (2-10), who had lost six games in a row and were winless in five previous road games.

John Wall had 23 points and 14 assists for the Wizards (5-5) in his return to the lineup. Wall sat out Washington's 107-96 win at Toronto on Sunday after injuring his left shoulder Friday in a home loss to the Cleveland Cavaliers.

Bradley Beal also scored 23 points for the Wizards, who have lost 14 of their last 15 meetings with the Mavericks.

Dallas led 64-53 at halftime and by as many as 16 points in the second half. After Washington closed to within 90-88 with 9:09 remaining, the Mavericks pushed back with a 15-5 run.

"We came into the game with a great collective force and collective will," Mavericks coach Rick Carlisle said. "We've been getting kicked around and it's no fun. Tonight our guys drew a line in the sand and really brought things to another level defensively."

Washington only shot 42.7 percent from the field against one of the league's worst defenses and showed little resolve in its third consecutive home loss. The Wizards opened the season 3-0 but have lost five of their last seven.

Dallas ranked 28th in scoring with 97.9 points per game, which made its first-half production surprising -- except to Washington observers. The Wizards surrendered 122 and 130 points in home losses last week to the Phoenix Suns and the Cavaliers.

"We tried to outscore people the last couple of games," Wall said. "We're not a team that can just outscore anybody. You have to be able to guard in this league, and we haven't done that at the beginning of this season."

Barnes sank 11 of 18 shots as Dallas hit 47.3 percent of its field-goal attempts.

"I guess they didn't think I was a good iso (isolation) scorer. I had to make them pay," Barnes said.

Washington trailed 90-74 after Matthews sank a 3-pointer with 55 seconds remaining in the third quarter. The Wizards scored the next 14 points, capped by a four-point sequence as Dirk Nowitzki received a technical foul after Washington's Otto Porter Jr. converted a three-point play.

But Dallas scored the next five points and eventually led 104-91 with 4:19 left.

Salah Mejri had 10 points, 12 rebounds and five blocks off the bench for Dallas, which also committed just 12 turnovers. The Wizards gave the ball away 15 times.

"We've been hurt in two major statistical areas. A lot of turnovers and not enough rebounds," Carlisle said. "Tonight we kept the turnovers down. ... Then beating them on the boards 53-39. It tells the story."

The Mavericks entered Tuesday allowing opponents to sink 48 percent of their field-goal attempts while ranking 29th in hitting shots from the floor (42.0 percent).

Leading 36-34 after the first quarter, the Mavericks opened the second with a 9-0 run and eventually led 64-49. Barnes scored nine of 16 first-half points in the second quarter.

"Pretty much the same thing," Beal said of another defense-optional home loss. "I probably sound insane trying to tell you something different, but it's the same thing over and over. We developed a bad habit of not coming out with energy."

Playing with athletic tape on the injured shoulder, Wall had 19 points and nine assists in the first half.

Beal averaged 38 points over his previous three games.

NOTES: Dallas F Dorian Finney-Smith (left knee soreness) had five points in 16 minutes after sitting out the previous four games. ... Wizards G John Wall made all eight of his free-throw attempts in the first quarter and finished 13 of 18. Wall missed 11 of 16 in his two previous games, including a 5-of-12 performance on Friday, when he injured his left shoulder. ... Dallas is off until Saturday, when the Cleveland Cavaliers visit. ... The Wizards close out their season series with the Lakers on Thursday. Los Angeles won the first meeting 102-99 in overtime on Oct. 25 after Washington blew a double-digit lead in the fourth quarter.