WASHINGTON — The Washington Wizards are in the playoffs for the first time since 2008, clinching an Eastern Conference berth Wednesday night with a 118-92 victory against the Boston Celtics.

Marcin Gortat scored 22 points to lead the Wizards, who gathered for a celebratory huddle at midcourt after the final whistle. John Wall, the 2010 No. 1 overall draft pick playing the first meaningful late-season games of his career, added 13 points and 10 assists.

The Wizards’ playoff position had been relatively secure for several weeks in the weakened East, but the formality of seeing the magic number reach zero was a milestone worth noting for a franchise whose win totals since their last postseason appearance have been 19, 26, 23, 20 and 29, never finishing better than 24 games below .500. Washington sits in sixth place in the conference.

Jared Sullinger had 25 points, and Rajon Rondo had 13 to lead the Celtics, who have lost six straight and 11 of 12, and also 11 straight on the road. They never led the Wizards, trailed 19-4 after barely more than five minutes and allowed Washington to shoot 61 percent in the first half. They shot 4 of 18 with six turnovers in the third quarter and 3 for 24 from 3-point range for the game.

Gortat went 10 of 13 from the field, and Bradley Beal 7 of 8 to finish with 19 points. The Wizards shot 62.5 percent, their highest game percentage in 13 years, and all five starters scored in double figures, rendering superfluous the customary off-the-bench burst from Coach Randy Wittman’s “AARP group” of Al Harrington, Andre Miller and Drew Gooden.

The Wizards’ last playoff appearance ended a streak of four straight with Coach Eddie Jordan and franchise point guard Gilbert Arenas. More was expected, but Arenas brought guns into the locker room and became a felon, precipitating a stunning decline for himself and the franchise.

The team president, Ernie Grunfeld, got rid of Jordan and went through two more coaches before settling on Wittman, whose career record is 141 games below .500.

Grunfeld misfired on draft picks and other signings, but the Wizards’ miserable records allowed him to land two cornerstones: Wall and 2012 No. 3 overall pick Beal.

 

NOTES: Celtics guard Avery Bradley missed the game with a strained right Achilles. He was hurt in the first half of Monday’s loss to the Chicago Bulls. … The Wizards committed 21 turnovers, the Celtics had 16. … It was the largest margin of victory this season for Washington as well as the biggest defeat for Boston. … The Celtics also had a 10-game road losing streak the last time they visited D.C. They won that game 113-111 in overtime on Jan. 22.