1. With Kristaps Porzingis, Al Horford, and Luke Kornet all out, the Celtics started the game against the Magic undersized, with Lamar Stevens at center.

This allowed the hosts to switch any matchup, which benefited them defensively, but Stevens hampered their spacing by operating almost exclusively from the dunker position.

2. Payton Pritchard came off the bench for Boston in the first period and offered a spark.

He had nine points and two assists. In a one-on-one matchup, the former Oregon Duck played well defending Paolo Banchero, who settled for a missed mid-range fadeaway from the baseline. Pritchard had the highest plus-minus rating entering the second quarter, with a plus-12.

3. There were times when the Celtics needed to switch faster and stay ahead of drives that were too easily converted into baskets at the rim. However, their versatility and intensity resulted in Orlando shooting 1/6 from beyond the arc and scoring only 24 points in the first period.

4. Jaylen Brown and Jayson Tatum continuously attacked downhill on the other end of the floor. They benefited from successful screens, including a few designed by Neemias Queta, but they also benefited from transition and one-on-one interactions.

Brown had ten points and was the only player on either team to score in double figures. Tatum scored seven points to help Boston take a 30-24 lead into the second quarter.

5. The ball movement of the hosts was excellent in the first half. They assisted on nine of their fifteen second-quarter field goals, 16 of their first 24 in the first half, and 18/27 in the first 24 minutes.

They scored 36 points in the paint and frequently created excellent opportunities thanks to solid screens and aggressive downhill attacking.

6. Despite playing inside-out basketball and creating decent shots from beyond the arc, the Celtics only made 7/22 (31.8 percent) of their threes. With it and the Magic’s nine second-chance points, the visitors stayed within 13 points at halftime, losing 64-51.

Nonetheless, they had difficulty keeping Tatum and Brown away from the basket. At the half, the former led all contestants with 18 points. The latter, who had 14, churned out poster after poster.

7. The Celtics are frequently at their weakest in the third quarter, and 10 foul calls before the four-minute mark on Friday created a choppy tempo of play.

But Boston, a club that has a habit of straying from how it builds large leads, stayed focused and dedicated to playing the correct way, pushing the pace and attacking downhill.

The hosts were everywhere on defense, blocking drives, challenging shots, and forcing six turnovers.

And, while it’s customary for teams on the second half of a back-to-back to start strong before fading after halftime, the C’s never let up, increasing their lead to 101-78 into the final 12 minutes.

8. And, with Boston continuing to throttle down in the last frame, there was never a moment to consider Orlando attempting a comeback.

With the advantage increasing to 25 points, Jaylen Brown and Jrue Holiday sat out the fourth quarter, while Jayson Tatum and Derrick White played fewer than nine minutes – more than they needed to – giving the starters much-needed rest at the end of their third game in four days. It’s also the second half of a back-to-back, with two days between games.

9. The Celtics will face the Magic again on Sunday afternoon at TD Garden. The second half of this two-part mini-series will begin at 3 p.m. EST.