Celtics forward Jayson Tatum goes to the basket past Wizards forward Rui Hachimura during the Celtics’ 116-87 win on Sunday in Washington. Nick Wass/Associated Press

WASHINGTON — This was quite a way for Jayson Tatum to break out of his shooting slump.

Tatum scored 51 points – 48 in the first three quarters – to help the Boston Celtics breeze to a 116-87 victory over the Washington Wizards on Sunday.

Tatum made a career-high nine 3-pointers and shot 18 of 28 from the field. That was after he shot 0 for 17 beyond the arc in his previous three games.

“When you’re missing shots, you know what you’re capable of, and sometimes you’ve got to laugh it off,” Tatum said. “It’s as simple as sometimes you just don’t make shots. You play so many games.”

Tatum had 31 points by halftime and reached 50 on a drive to the basket with about 4:30 remaining. He added a technical-foul free throw with 3:55 to play and then checked out of the game while the crowd in Washington, which included plenty of green-clad Boston fans, gave him a standing ovation.

“That’s an incredible feeling,” Tatum said. “Seeing so many fans on the road with a Tatum ‘0’ jersey on – something I don’t take for granted. I understand there’s 450 some-odd guys in the league, and they took the time to go buy my jersey.”

Bradley Beal scored 19 points for the Wizards, who never led in Coach Wes Unseld Jr.’s return from being on the COVID-19 health and safety protocol list.

Washington, which has one game remaining on an eight-game homestand, has dropped three in a row.

Boston led 46-45 in the second quarter, but Tatum’s 17-footer started a 14-0 run to close the half. Tatum added a couple free throws and two 3-pointers during that stretch and finished with 18 points in the quarter.

“It pretty much came down to the end of the second quarter,” Unseld said. “Essentially, that was the game.”

Tatum reached 40 points with a couple free throws with 4:48 left in the third.

Moments later, a dunk put him even with his season high of 42 that he set last month against Milwaukee.

He added two more 3s before the quarter was over, the second of which put Boston up 89-62.

“To Tatum’s credit, he had a night,” Unseld said. “Obviously, 51 points, it’s a real number. I think he was 6 for 8 on pull-up 3s, which are tough shots. No excuse. He’s been struggling, but he found his rhythm tonight.”

Tatum seemed to realize his day might be done, taking three more shots in the final minute of the third quarter, all misses.

He ended the third a bucket shy of 50 and left the game.

But he came back with 7:21 left in the fourth and scored enough to surpass 50 – although he remained well shy of his career high of 60, set against San Antonio last April.

Tatum was aware how close he was to 50 when he went back in. Celtics Coach Ime Udoka said that wasn’t a factor in putting him in, though.

“We were getting a little iso-heavy, stagnant there,” Udoka said. “We’ve obviously had our troubles closing, so, get him back in and try to finish the game.”

Boston’s Marcus Smart played for the first time since Jan. 10 after he went through health and safety protocols. He scored 11 points.

Jaylen Brown scored 18 points with 10 rebounds. Tatum also had 10 rebounds.