ISAIAH THOMAS led the Celtics to a first-round win over Chicago in a haze after learning the day before that series began that his younger sister, Chyna Thomas, had died in a car accident outside of his native Tacoma, Washington.

That pain persisted on the eve of Boston’s second-round pairing with the Washington Wizards, when he flew cross-country to attend her funeral.

Then Sunday’s game brought the latest dose of adversity, when he had one of his front teeth dislodged after an early game collision.

But as he’s done all postseason, he continued to find a way to push through it.

Thomas had 33 points and nine assists, and the Celtics made 19 3-pointers to beat the Wizards 123-111 and take a 1-0 lead in their Eastern Conference semifinal matchup.

“I got in at 4 a.m.,” Thomas said of his second flight to Washington in two weeks. “It’s tough, but it’s the playoffs so there are no excuses. I decided to play and I just tried to give it all for my team.”

The Celtics star flew to the funeral with Boston president of basketball operations Danny Ainge and assistant coach Jerome Allen.

During player introductions, Thomas pointed to the TD Garden rafters when his name was called.

Al Horford added 21 points, 10 rebounds and nine assists. Jae Crowder finished with career playoff-high 24 points.

Game 2 is set for tonight.

The Wizards were more energetic at the outset, jumping out to a 16-0 advantage and leading by as many as 17 points.

But the Celtics rallied with Thomas briefly sidelined while getting his tooth repositioned in the second quarter.

(SD-Agencies)