The Wizards are sixth in the East -- one game behind Brooklyn and one ahead of Charlotte -- and can lock up the fifth seed with a win and a Nets loss at Cleveland. The Wizards, who have the tiebreaker against Brooklyn, can sew up the No. 6 seed with a victory over the Celtics, but will drop to seventh if they lose and the Bobcats prevail versus Chicago.
Charlotte went 3-1 against the Wizards this season. The seventh seed has a date with the two-time defending champion Miami Heat in the first round.
Washington handed the Heat a 114-93 loss on Monday, but didn't face LeBron James or Chris Bosh. Trevor Ariza scored 25 points, Nene added 18 and Al Harrington netted 16 points for the Wizards, who shot 59 percent for the game and sank 14-of-29 3-pointers. They had a 70-48 lead by halftime and shot 70.3 percent in the first half.
Bradley Beal scored 15 points, Marcin Gortat ended with 10 and 13 rebounds and John Wall chipped in four points and 13 assists in the win, Washington's seventh in the last 10 tries. Wall was averaging 19.1 points since the All- Star break.
"I want them to continue, even with one game left, to build and use that game as something positive going into the playoffs," said Wizards head coach Randy Wittman.
The Wizards go for their third straight road win and are 21-19 outside the nation's capital. They are in the playoffs for the first time since 2007-08.
Boston is closing out its re-building season and will not participate in the playoffs for the first time since 2006-07.
The Celtics were aiming for a three-game winning streak, but instead dropped a 113-108 decision in south Philly Monday night for their 15th loss in 18 tries. Rookie Kelly Olynyk (28), Jeff Green (27) and Avery Bradley (23) all scored more than 20 points and it wasn't enough to stay in the win column.
Olynyk's 28 points were a career high.
"There are a couple guys sidelined with injuries, so other guys have to step in and pick up the load," Olynyk said. "I just figured this would be a good time to do it."
Rajon Rondo ended with eight points, 14 assists and 11 rebounds for the Celtics, who made a respectable 47 percent from the field and didn't have Jerryd Bayless (knee) or Jared Sullinger (ankle).
Boston fans will get to see their team for the final time this season and the Celtics have a 16-24 record at TD Bank Garden. The Celtics have lost five of their last seven in front of the home crowd.
"Those fans have been phenomenal all year. We've had our struggles and they've been behind us the whole time, which has been unbelievable," Olynyk said. "I would say they are definitely the best fans in the league. Even with our situation, they still go out and give a whole-hearted effort. We owe it to them to come out and play as hard as we can and try to get one for them."
The Celtics are 1-2 against Washington this season, but have won eight of 10 and nine of the past 12 games in this series. The Wizards have lost six of seven and 10 of 13 trips to Beantown.