"Rajon threw a perfect pass and I just banked it," Garnett said. "The crazy part about all that is that I messed that play up so many times in practice. It's only right that the basketball gods gave it to me tonight. It was a good win for us, a grind-out win. This team has been playing unbelievably."
After Philadelphia's Andre Iguodala drove for a hook shot with 6.6 seconds left to give Philadelphia a 101-100 lead, Rondo flipped a pass from just outside the 3-point line to Garnett for the winner.
"We worked on that last week," Celtics coach Doc Rivers said. "We tried to run it early and had bad timing. It's just funny how things work out. It's a low-clock play. The ball's in the best passer's hands, and you have shooters on the floor. The whole sell was Paul Pierce and it worked."
Garnett then ended the game by intercepting the 76ers' inbounds pass.
"It was a gutsy win," Pierce said. "It didn't seem like we had it all night. We couldn't get really consistent momentum in the game or get a consistent flow. But good teams find a way to win. There was good execution down the stretch."
Trailing 80-72 with 2:39 left in the third, the Celtics rallied with a 9-0 run -- pulling ahead 81-80 lead on Rondo's 3-pointer with 0.9 seconds left in the period to set up a tight fourth quarter that featured 14 lead changes.
Iguodala gave the Sixers two leads in the closing minute. Davis erased the first one with a 15-foot jumper before Garnett's winner.
A crowd of 17,948 -- the 76ers' second-largest of the season -- packed into the Wells Fargo Center, many of them decked out in green and white.
Neither team led by more than eight points.
"What a heartbreaking loss," 76ers coach Doug Collins said. "They have so many different ways that they can attack on the offensive end. It was just a shame. It would have been an incredible win for us here tonight."
Shaquille O'Neal, averaging 11.2 points this season for Boston, missed the game because of a sore right calf, while Jermaine O'Neal sat out with a sore left knee. ... Boston has won 11 of its last 13 games against Philadelphia and leads the series 238-176. ... Brand has seven double-doubles this season -- matching his total from 2009-10 -- and 368 in his career.
Bob Ryan believes former head of FIBA Borislav Stankovic's insistence to have foreign players take their talents to the NBA played a direct result in the most international players being taken in the first round of the 2016 NBA draft.
Denzel Valentine could land in Chicago's rotation after Derrick Rose departed for New York.
No. 1 draft pick Ben Simmons said hearing the news of the death of his cousin "is a reminder to never forget the important things in life."