PHILADELPHIA — The Boston Celtics and Philadelphia 76ers played their first clutch game of the series and it was the Celtics who made the winning plays down the stretch. Everyone chipped in as the Celtics won Game 3 and took back home court advantage.  Here are six reasons why they won Jaylen Brown Took Over With 7:04 to play in a one-point game, Brown came up with a steal and an assist to a cutting Derrick White.  It was part of an 8-0 run that reclaimed the lead.  “All your preparation and stuff comes down to those moments,” Brown said. “Both teams are tired, your team is maybe offensively in a little bit of a rut, you’ve got to figure out how to get a basket, you’ve got to figure out how to create some momentum for your team, and I feel like I did just enough to shift things in our favor.” The Celtics never trailed again, so Brown gave them just enough of a pad to hold on.…