KISSIMMEE, Fla. – Game 1 goes to the Boston Celtics.

They defeated the 76ers, 109-101, Monday night to take a 1-0 lead in the best of seven series. Game 2 is 6:30 p.m. Wednesday.

Jayson Tatum and Jaylen Brown had a lot to do with the outcome, combining for 61 points.

Tatum finished with game highs of 32 points and three blocks to go with 13 rebounds. The 22-year-old became the youngest Celtic to finish with at least 30 points and 10 rebounds in a playoff game. Twenty-one of the All-Star forward’s points came in the first half.

While Tatum had a huge first half, Brown came up big in the fourth quarter. That’s when the shooting guard finished with 15 points on 4-for-5 shooting, including going 3-of-3 on three-pointers. He finished the game with 29 points while making 5 of 8 three-pointers.

“Who wants it the most? Who wants to fight?” Brown said of his and Tatum’s playing off each other. “Today we came out and we battled with a more physical team. We battled and I was proud of us.

“We got to keep that fight up if we want to win this series.”

Joel Embiid paced the Sixers with 26 points on 8-for-15 shooting and a game-high 16 rebounds. The three-time All-Star needs to get more shots for Philly to have a chance to compete in this series.

He got five shots in the fourth quarter, missing four of them en route to scoring seven points in the period.

“Obviously, that’s not enough,” he said of his shot attempts. “It’s just whatever. We had a couple of guys that had it going, and it’s nothing to really say.

“But I guess, especially with the way I started in the first quarter, I just need to be more assertive, and demand the ball. Just be aggressive.”

Embiid scored 11 points on 5-for-5 shooting in the first quarter. He took only two shots in the second quarter, missing both. In the third quarter, he shot 2-for-3 to score six points.

“Whatever the stats are, I’ve got to do more,” Embiid said. “I’ve got one job to do — carry us. I’m going to need my teammates to help me, but I need to do more.

“I’ve got to take more shots, I’ve got to be more aggressive, I’ve got to help my teammates.”

The Sixers also need to do a better of handling the ball. They had 18 turnovers, compared with seven by the Celtics. Embiid had five of those turnovers.

Celtics forward Gordon Hayward suffered a sprained right ankle in the fourth quarter and didn’t return.

“I don’t know the severity, but he’s clearly in pain,” Boston coach Brad Stevens said. “It looked like it had some swelling already.”

The Sixers’ starting lineup was one of the biggest questions heading into this series. Coach Brett Brown acknowledged Sunday that he was considering starting standout rookie Matisse Thybulle for defensive purposes against the Celtics’ four talented perimeter players -- Tatum, Brown, Hayward, and Kemba Walker.

The Sixers are also without injured two-time All-Star Ben Simmons, their best defender.

With Simmons out, the Sixers don’t match up well against the Celtics defensively.

Richardson and Thybulle are legitimate perimeter defenders. But the Sixers went with their normal starting lineup of Tobias Harris, Al Horford, Embiid, Richardson, and Shake Milton.

Thybulle ended with two steals, one block, and five points in 32 minutes, 41 seconds of action. He did a solid job against the Tatum. The 6-foot-8, 210-pounder scored four points on 2-for-9 shooting, including going 0-for-1 from three-point land, while being guarded by the rookie. Thybulle blocked the three. Meanwhile, Tatum scored 28 points on 8-for-12 shooting, including going 2 of 4 on threes against the other Sixers.

“J-Rich’s minutes [37:11] and Matisse’s minutes, they’re completely mirrored to Kemba [34:42] and Jayson’s [41:27],” Brett Brown said. “So I think that to blow up the starting five in exchange for doing that, I’m not prepared to say that’s going to happen.”

He will look at the tape and consider that option.

Thybulle checked in for Horford with 6 minutes, 28 seconds left in the first quarter and made a quick impact. He blocked Tatum’s three-point attempt on his second defensive possession.

Then Thybulle’s three-pointer with 2:44 left in the quarter gave the Sixers a 23-19 advantage. Philly took a 26-25 lead into the second quarter.

The Celtics took the lead and built a double-digit advantage (53-43) after Brown took Thybulle off the dribble to score a layup with 1:33 before intermission. The Sixers pulled within six points thanks to Richardson’s going on a personal 7-2 run to end the half.

Harris’ seven assist in the first half tied a season high for a game. He finished with 15 points and eight assists.

The Sixers had two problems n the first two quarters -- Tatum and turnovers.

Tatum’s 21 first-half point were the most by a Celtic in a postseason half since Avery Bradley in 2017. The Sixers didn’t help themselves, committing 13 first-half turnovers. They led to 16 Celtics points.

In the third quarter, Boston built an 11-point cushion. However, the Sixers ended the quarter with a 15-0 run to take a 81-75 lead on Embiid’s jumper 24 seconds into the fourth quarter.

The Celtics responded with a 26-10 run to take a 101-91 lead on Walker’s layup with 3:19 left. But the Sixers pulled with three points (103-100) after Richarsdson’s three-pointers with 59.1 seconds left.

But Tatum then sandwiched four foul shots around a pair by Kemba Walker to give Boston an eight-point victory.

This was Sixers assistant John Bryant’s first game in the bubble. He arrived late because his wife was having a baby. Juan Jackson, the Sixers’ director of team security, is no longer in the bubble.