After a slow start, Derrick White finished with 18 points.
After a slow start, Derrick White finished with 18 points.Matt Rourke/Associated Press
PHILADELPHIA — The Celtics and 76ers have their flaws and plenty that must be figured out as this season progresses. But if one thing is clear, it is that right now they are essentially equals.
The teams split their first two matchups this season in 1-point games, and the third on Tuesday night was just as tense and taut. This time, the Celtics wiped away a clumsy first half with a powerful third quarter.
But their 8-point fourth-quarter lead did not hold up, as a Kelly Oubre putback with 8.7 seconds left gave the 76ers the lead, and Boston’s ensuing broken play ended with a desperation 3-pointer by Derrick White that was off, allowing Philadelphia to escape with a 102-100 win.
Jaylen Brown had 24 points to lead the Celtics. Justin Edwards came off the bench and hit 8 of 9 shots and scored 22 points to lead the 76ers. Philadelphia was without former MVP Joel Embiid, who was sidelined because of knee soreness.
The Celtics took an 8-point lead midway through the fourth, buoyed by a pair of 3-pointers by Anfernee Simons. But Edwards pulled the 76ers within 92-87 with a 3-pointer before rookie VJ Edgecombe had a dazzling blocked shot on a Brown dunk attempt that led to another Edwards three in transition.
After a White miss, Edwards connected on his third 3-pointer in an 80-second stretch, making him 8 for 8 from the field and giving the 76ers a 93-92 lead with 4:41 left.
With the 76ers leading, 97-96, Edgecombe, who was just 1 for 10 from the field, saw a 3-pointer carom high off the back rim before falling through the net with 2:17 left.
White answered with a 3-pointer, and Walsh smothered Tyrese Maxey on consecutive possessions before Brown was fouled with 33.5 seconds left. He hit one of two free throws to tie the score at 100.
Walsh once again bothered Maxey on his drive, forcing him to kick the ball out to Edwards, who missed for the first time. But Oubre was there for the putback with 8.7 seconds left.
After a timeout, White had the ball knocked away. He chased it down a few from midcourt with about four seconds left and fired up a 3-pointer from there. It was not close, and Neemias Queta’s tip-in attempt was off.
White, who has struggled on offense this season, converted a runner on Boston’s first possession. But that did nothing to get him untracked.
He missed his other seven first-half shots, including five 3-pointers. The last was most puzzling. Late in the second quarter, White was wide open when he caught a pass in the left corner. He had time to measure the shot and check his feet, but the attempt skidded off the rim anyway.
White then stood and held his follow-through for several moments, clearly frustrated. But the 76ers did not wait for him as they rushed upcourt and converted a fast break.
White’s teammates found no rhythm in the first half, either. Brown missed his first five shots before converting a mid-range jumper with 3:16 left in the second quarter. Payton Pritchard was 0 for 5, 0 for 3 from the 3-point line.
At the start of the second quarter, in an attempt to generate offense with frenetic defense, coach Joe Mazzulla once again turned to Hugo Gonzalez and Jordan Walsh.
But at the other end, the 76ers frequently left Walsh in order to seek double-teams elsewhere. He missed his first four shots, including a pair of 3-pointers.
When the 76ers left him open on the final possession of the half to double-team Brown, Walsh finally capitalized by surging into the lane for a two-handed dunk that pulled Boston within 51-41. It felt like a necessary momentum jolt.
The Celtics made just 14 of 50 shots (28 percent) and 4 of 21 3-pointers (19 percent) in the opening half. Still, the deficit was manageable despite those lousy numbers.
Walsh started the second half in place of Josh Minott, and the swap paid instant dividends. He streaked in and grabbed a Queta miss before finding Pritchard for a layup. He swatted Trendon Watford’s attempt in the paint. He threw down a fast-break dunk. He came up with a steal that led to a White 3-pointer.
It was the energy the Celtics needed. The team’s two stars took it from there. Brown and White, who looked uneasy and discouraged in the first half, could not miss in the third quarter.
First, it was Brown, who kept the 76ers off balance with a dizzying array of mid-range jumpers. Then it was White, who hesitated on that wide-open 3-pointer in the second quarter and suddenly began spraying them while guarded closely.
He drilled two in the final 33 seconds of the quarter to cap a massive 36-17 surge to start the quarter. The 76ers, who started the quarter 6 of 25 from the field, slowed the momentum with a Quentin Grimes halfcourt shot at the buzzer.
Adam Himmelsbach can be reached at adam.himmelsbach@globe.com. Follow him @adamhimmelsbach.