BOSTON — The Celtics needed Al Horford to outplay or slow down Philadelphia 76ers star Joel Embiid for Boston to have a real chance of winning their second-round NBA playoff series.

Horford, through two games, has done that job very well, and the Celtics lead the series 2-0 as a result.

Embiid scored 20 points in Thursday night’s Game 2 at TD Garden, but he missed 14 of 22 shots and five of his six 3-point attempts. Horford was physical with Embiid on the low block, contested his shots and didn’t let the 76ers center score easy buckets in transition.

The Celtics big man finished with 13 points, and his final two points essentially sealed Boston’s 108-103 victory. Horford had Embiid on the perimeter, saw he wasn’t in the best position laterally and drove to the basket for a layup that put the C’s up 106-101 with 8.3 seconds remaining in the fourth quarter.

One of the advantages to Horford’s matchup versus Embiid from a Boston perspective is it brings the 76ers center outside of the paint on defense. Embiid has to come out of the paint and guard Horford on the perimeter because the Celtics star is one of the league’s best 3-point shooters. With a Embiid around the 3-point line, Philly doesn’t have any rim protection, and that allows Celtics scorers, including Terry Rozier and Jayson Tatum, to drive to the basket and finish at the rim.

Horford also attacked Embiid often on drives to the basket and picked up a few fouls on the All-Star center. Embiid’s defense was poor for the last half of the fourth quarter because his aggression was gone out of fear of fouling out.

The 76ers need Embiid to be a dominant scorer and not get into foul trouble if they are going to win this series. So far, he hasn’t done enough at both ends of the floor for the 76ers to get a win in Boston, something they must achieve with the Celtics having homecourt advantage.

Here are some other notes from Game 2:

— Jaylen Brown made his first appearance in the series and received a loud ovation after coming off the bench early in the first quarter. His hamstring looked pretty good after he outran two 76ers for a loose ball and threw down a powerful dunk on his first taste of real action in several days. He didn’t shoot well early on, hitting just one of his first attempts, but the Celtics guard finished with 13 points on 5-for-12 shooting.

— The Celtics closed the second quarter with an 18-3 run over the final 3:30 that cut the lead to 56-51 at halftime after the 76ers, at one point, held a 22-point edge. Boston shot 7-for-10 — including 4-for-6 — from beyond the arc during this run. Strangely, Sixers head coach Brett Brown decided not to call any timeouts during this Celtics blitz, despite having a very young, inexperienced team that wasn’t handling the sudden change of momentum well.

— Celtics guard Marcus Smart started over Brown and scored a playoff-high 19 points on 6-for-13 shooting. He made four 3-pointers.

Terry Rozier also played a lead scoring role for the C’s.

— The Celtics turned the ball over just nine times, two less than the Sixers. In fact, Boston went 27 straight possessions without a turnover for a stretch of time in the second half.

— Jayson Tatum’s rookie season continues to impress.

— Aron Baynes went 1-for-3 from behind the arc and now is 3-for-6 from 3-point range in this series. His five made 3s in the playoffs are more than he’s hit over his entire career.

— The Celtics now have beaten the 76ers twice this season when trailing by 21 or more points. Their other such win was in London in January.

The Celtics have won a lot of games this season when their win probability was very, very low.

— 76ers guard JJ Redick led all scorers with 15 first-half points and finished with a team-high 23 on 9-for-17 shooting, including a 5-for-9 mark on 3-pointers. His red-hot shooting from beyond the arc was the catalyst to Philly opening up a 22-point first-half lead.

— The 76ers made seven of their first 11 shots from 3-point range, then cooled off and connected on just eight of their next 25 3-point attempts.

— Ben Simmons probably will win Rookie of the Year, but he was a no-show in Game 2. He scored only one point on 0-for-4 shooting. Simmons almost averaged a triple-double versus the Miami Heat in the first round, but he’s been largely ineffective in this series.

Thumbnail photo via David Butler II/USA TODAY Sports