The Sixers were handily defeated 117-98 by the visiting Dallas Mavericks on Friday for their second straight home loss after winning their first 14 to open the season.
The Sixers have not lost four games in a row all season.
Over the last two home games -- losses to the Miami Heat and Mavericks -- the Sixers have struggled against zone defenses.
"This is not who we are. It's not who we are," Sixers head coach Brett Brown said. "I love coaching these guys because I respect them. I feel like our competitive spirit has been bent. ... The last three games we have laid eggs. We have not played with a competitive drive that reflects this team."
All-Star center Joel Embiid did manage to post his 19th double-double with 33 points and 17 rebounds, and Ben Simmons added 12 points, eight assists and six rebounds, but it wasn't enough to overcome the Mavericks' zone defense.
The Sixers were also outrebounded by the Mavericks and dropped to 1-6 this season when that happens.
"We're not playing good enough defensively," said forward Al Horford, who scored nine points against the Mavericks. "We like to play fast. It (zone) gets us stagnant."
The Wizards have already defeated the Sixers once this season, winning 119-113 at home on Dec. 5.
"I feel like we should have won," Beal told reporters. "We had enough flow and juice to win. Down the stretch, we kind of got away from ourselves. We weren't defending. They made some tough shots down the stretch, too."
Smith became the first Wizards bench player to have a perfect shooting night with a minimum of nine attempts since the statistic was first introduced in 1971.
Smith was 4 for 4 from beyond the 3-point arc and 4 for 4 from the free throw line.
"I expect him not to miss tomorrow night, either," Wizards head coach Scott Brooks quipped of Smith facing the Sixers.
Davis Bertans added 10 points for Washington, but was 2 for 12 on treys. Bertans had been one of the hotter long distance shooters in the league in recent weeks.
Washington is also short-handed and will likely be without forward Rui Hachimura (groin) for a third straight game and center Moritz Wagner (left ankle) for a fifth consecutive game.
Hachimura, the No. 9 overall pick from Gonzaga in last June's draft, had been one of only five rookies this season to average at least 12 points and five rebounds before getting injured.
The Wizards are already likely playing the rest of the season without All-Star guard John Wall.
--Field Level Media