Irving’s efforts were aided by 18 points from Jaylen Brown and 15 from Marcus Morris for Boston, which remained a game up on Toronto atop the East standings after the Raptors’ win in New York, Reuters reported.
Otto Porter Jr. had 27 points and Bradley Beal netted 18 for the Wizards, who were playing their seventh straight game without John Wall after the All-Star point guard underwent left knee surgery.
Boston bounced back from a 111-91 rout in Toronto on Tuesday to win for the fifth time in six games. Washington has dropped two in a row after its season-high, five-game winning streak.
Greg Monroe had five points and six rebounds in 20 minutes off the bench in his Celtics debut after signing with Boston earlier in the day following a buyout from the Phoenix Suns.
Brown’s three-pointer beat the shot clock to put Boston up 108-103 with 1:43 left in overtime. Kelly Oubre Jr. made one of two free throws with 1:14 to go to bring Washington within four.
After missed three-point attempts by Beal and Porter, Irving claimed a rebound and was fouled by Beal with 15.5 ticks to go. Irving made both free throws to seal the win.
Boston trailed 51-49 at halftime but outscored Washington 26-19 in a pivotal third quarter to open a 75-70 advantage heading into the fourth.
Porter hit a pair of free throws with 12.8 second to go to in regulation give the Wizards a 98-95 edge. Irving was fouled by Markieff Morris on a leaning three-point attempt with 9.8 seconds left and made all three free throws to tie it.
Beal’s turnaround jumper at the buzzer was off target, forcing overtime.
Boston opens a three-game homestand Friday against Indiana. Washington kicks off a three-game trip Saturday in Chicago.
Kevin Durant scored 13 of his game-high 24 points in the third quarter Thursday night, allowing the Golden State Warriors to overcome a sluggish start in a 121-103 victory over the Dallas Mavericks in Oakland, Calif.
Golden State’s Stephen Curry moved ahead of Vince Carter on the NBA’s all-time list for three-pointers, sinking four to account for more than half his 20 points.
The Warriors rebounded from their first two-game losing streak of the season.
Rookie Dennis Smith Jr. had a team-high 22 points for the Mavericks, who lost for the seventh time in their past eight games.
Dallas played without leading scorer Harrison Barnes, out with a sprained left ankle, and Devin Harris, traded earlier in the day to the Denver Nuggets in a three-team deal that resulted in Doug McDermott being acquired by the Mavericks from the New York Knicks. Dallas also picked up a second-round pick from Denver in the swap.
The Mavericks led by as many as 10 points in the first quarter and 12 in the second. However, Golden State rallied into a 60-all halftime tie, then took charge for good with a 17-6 burst over the final 4:23 of the third period that opened a 93-85 lead.
Durant contributed two three-pointers, a dunk, two free throws and an assist to the run.
Shaun Livingston scored from the interior, David West slammed home a dunk and Klay Thompson bombed in a three-pointer as Golden State scored the first seven points of the fourth quarter to build a 15-point advantage before coasting home.
Thompson finished with 18 points on his 28th birthday, and Draymond Green registered 12 points, 10 rebounds and six assists for the Warriors, who swept the four-game season series from the Mavericks with their 10th straight win over Dallas.
Green got nailed with his league-leading 14th technical foul in the first half. Earlier in the day, he learned he had been fined $50,000 for using inappropriate language toward a referee Tuesday in a loss to the Oklahoma City Thunder.
Curry’s four three-pointers gave him 2,086, four more than Carter has accumulated in his ongoing NBA career.
Dwight Powell had 18 points, Wesley Matthews 17 and Dirk Nowitzki 16 for the Mavericks, who were coming off a 104-101 road loss against the Los Angeles Clippers on Monday.
Nowitzki, who added a game-high 11 rebounds, was playing for the first time since surpassing the 50,000-minute mark on Monday. He added 29 minutes to his total against Golden State.