The Boston Celtics beat the Philadelphia 76ers 125-120 in overtime Friday night in Philadelphia to finish the preseason with a perfect 4-0 record, NBC Sports Boston and NESN reported.

Boston sat most of its top players, including Jayson Tatum, Derrick White, Sam Hauser, Neemias Queta and Payton Pritchard, NBC Sports Boston reported. Philadelphia started Joel Embiid, LeBron James, Tyrese Maxey and Jaylen Brown, and NESN reported the four starters each played at least 24 minutes. Sam Cassell coached Boston while head coach Joe Mazzulla took the night off, NESN reported.

Hugo Gonzalez scored 21 points off the bench for Boston, and Ron Harper Jr. added 16 as the main ball handler late in the game, NBC Sports Boston reported. Gabe McGlothan grabbed 13 rebounds, five of them on the offensive glass, the outlet reported. NESN reported that rookie Chris Cenac Jr. had 12 points and eight rebounds.

Embiid led all scorers with 27 points, and Brown had 20 points, eight rebounds, three assists, a steal and two blocks in his first game against Boston, the team he played for 10 years, NESN reported. Brown did not dress when the teams met in Boston on Oct. 10, according to ESPN's box score. "I played there for 10 years, so it'll never be out of the way," Brown said, according to NBC Sports Boston. "But it was good to see some of the young guys."

The Celtics outscored Philadelphia 31-21 in the fourth quarter and 10-5 in overtime, NBC Sports Boston reported. Philadelphia's starters did not play much down the stretch, leaving the deeper parts of each bench to decide the game, NESN reported.

Boston opens the regular season Tuesday afternoon against the Pistons in Detroit, NBC Sports Boston and NESN reported.

What we know: Boston's reserves beat a Philadelphia lineup with its main starters to finish 4-0 in the preseason.
What we don't: How much of the bench's play will carry over once Boston's regulars return for the opener.