Jaylen Brown scored 32 points and Jayson Tatum added 30 as the Boston Celtics held off the Atlanta Hawks in a 128-120 thriller on Thursday to win their NBA Eastern Conference first-round playoff series four games to two.

The Celtics, trying to get back to the NBA Finals after falling last season to the Golden State Warriors, booked a conference semi-final showdown with a Philadelphia 76ers team led by Joel Embiid and James Harden.

Trae Young, hero of the Hawks' 119-117 come-from-behind victory in game five that extended the series on Tuesday, scored 30 points with 10 assists.

But Young ran out of steam in the second half, scoring just five points after the break and finishing the game nine-for-28 from the field.

The Celtics, stung after leading late on their home court in game five, clamped down in the final minutes to put away a game that featured 22 lead changes and 15 ties.

"I think in that fourth quarter, four minutes left, we made winning plays," Tatum told broadcaster TNT in an on-court interview.

"We talked about it before the game — do whatever it takes."

The lead changed hands seven times in the fourth quarter alone. Former Hawk Al Horford put the Celtics up for good with a three-pointer with 3:35 remaining.

Tatum followed with another three-pointer, Brown produced a block and Tatum slammed home a Horford miss to cap an 11-0 Boston run that had the Celtics up by eight with 2:07 to play.

Atlanta wouldn't get the deficit below five points the rest of the way.

The second-seeded Celtics, the highest seeds left in the East after the Miami Heat's upset of the top-seeded Milwaukee Bucks, host the third-seeded 76ers in game one on Monday.