DALLAS (AP) -- Dennis Smith Jr. scored his first points on a 360-degree dunk before the rookie Dallas guard focused more on the bigger task: trying to slow the high-scoring Washington duo of Bradley Beal and John Wall.
The Mavericks did that Monday night, holding the Wizards guards to 28 percent shooting in a 98-75 victory that completed a two-game season sweep of the Eastern Conference playoff contenders while easing Dallas' slide back toward to the bottom in the West.
Mavericks coach Rick Carlisle didn't want to give his players too much credit, though.
"I thought the defense certainly looks good on paper, but there were an awful lot of missed shots," Carlisle said. "They had a lot of looks where we weren't in the best position possible."
Washington coach Scott Brooks agreed.
"We couldn't make a wide-open shot, couldn't make a layup, and we couldn't even make non-contested free throws," Brooks said. "It was one of those nights."
Harrison Barnes had 20 points and 10 rebounds, Smith scored 17 and the Mavericks stopped their second three-game losing streak since the beginning of January.
Barnes, who scored a season-best 31 points in a 113-99 win at Washington in November, was 9 of 16 from the field.
Beal scored 18 and Wall had 11 -- the only double-digit scorers for the Wizards -- as the guards combined to go 8 of 29 from the field. Beal was 7 of 12 on free throws, and the Wizards were just 16 of 27 from the line.
Wall, who was a game-time decision because of a migraine, missed all four of his 3-point attempts as Washington went 7 of 32 from long range (22 percent) and shot 31 percent overall. The Wizards had their second-lowest point total behind a 116-69 loss at Utah in December.
"It was a little difficult trying to play through it, but there is no excuse for the way we played or how we got our tails whooped," Wall said.
Dirk Nowitzki had just two points when he converted a four-point play to start the fourth quarter to give Dallas its biggest lead to that point at 75-54.
Nowitzki, who finished with eight points and nine rebounds, hit his 3 before the foul by Mike Scott from the same left corner where Yogi Ferrell connected at the third-quarter buzzer. Ferrell scored 14 points along with Wesley Matthews, who was 4 of 8 from 3-point range.
Wizards: F Markieff Morris and Brooks got technicals in the first half. Morris was complaining about no-calls on fouls after he was called for one when he knocked the ball loose as Smith was going up for a dunk on a 3-on-1 break. Brooks got his in the final seconds of the half, not long after Morris was called for an offensive foul. … Porter left with a right hip strain and didn't return.
Mavericks: C Salah Mejri was ejected after getting two technicals when he kept arguing with official David Guthrie despite Matthews trying to push him away. … G Devin Harris is in the concussion protocol and missed the game. He was injured in Saturday's loss at Portland. … The Mavericks held an opponent to season lows in points in the first half (37) and the game.
Dallas guard J.J. Barea got a technical in the second half when he and Wall exchanged words after Barea fouled him in the fourth quarter. Asked about it afterward, Wall said, "It was cool. It was funny. Just a little midget trying to get mad out there. I paid him no mind."
At first, Barea shrugged off the "midget" comment, but he got slightly more agitated the more he talked about it after the game. "When they ask me who I don't like in the NBA, I got a guy now," Barea said. "Nothing new to him. I don't think even his teammates like him."
Smith and Beal ended up with their arms locked after a whistle, and stayed that way for several seconds. It led to a brief exchange, and wasn't the only time they could be seen talking during the game. "He's just like all rookies, they hate being called rook from the get-go," Beal said. "He wasn't having it, but at the end of the day, that's the title. We all went through the process at one point."
Wizards: At Oklahoma City on Thursday in fourth game of five-game trip, tied for their longest of the season. The teams will finish the two-game season series five days later in Washington.
Mavericks: Host Houston on Wednesday.