Jayson Tatum of the Boston Celtics shoots the ball against the Washington Wizards on Tuesday in Boston. Photo: VCG

Jayson Tatum erupted for 50 points as the Boston Celtics booked their place in the playoffs on Tuesday with a 118-100 win over the Washington Wizards as the NBA's play-in tournament got under way.

Tatum produced a virtuoso performance to outshine Wizards triple-double king Russell Westbrook as the Celtics advanced to a first round playoff series against the second-­seeded Brooklyn Nets.

The Wizards will now host the Indiana Pacers on Thursday, with the winner of that game facing a first round playoff series against the Philadelphia 76ers, the top seeds from the Eastern Conference.

"This is big," Tatum said ­afterward. "We wanted to come out and compete. Everybody played well and contributed. We're feeling good about ourselves."

An even first half at Boston's TD Garden on Tuesday saw Washington edge into 54-52 halftime lead before the Celtics and Tatum exploded in the third quarter to break the game open.

The Celtics outscored the Wizards 38-26 in the third period, with Tatum combining superbly with Kemba Walker to rapidly erase their half-time deficit and open up a 16-point lead.

That burst of scoring proved decisive with the Celtics keeping the Wizards at arm's length thereafter as they closed out the win.

The win marked a startling turnaround in form for the Celtics, who lost five of their six final regular season games.

Tatum finished with 50 points, eight rebounds and four assists - a tally that included a perfect 17 of 17 from the free throw line - while Walker had 29 points. Tristan Thompson ­added 12 points and 12 rebounds.

Bradley Beal led the Wizards scoring with 22 points while Westbrook finished with 20 points. Westbrook had a rare off night, making only six of 18 attempts from the field.

The Wizards must now rally themselves for Thursday's clash with Indiana, who looked red hot in a 144-117 blowout to eliminate the Charlotte Hornets in Tuesday's early play-in game.

Oshae Brissett scored 23 points and Doug McDermott added 21 as the Pacers got off to a fast start and never eased up in a comprehensive wire-to-wire victory in Indianapolis.

Domantas Sabonis added 14 points and hauled down 21 rebounds with nine assists in a dominant display.

"I feel like everybody's confidence is the highest it's been all year," Sabonis said.