Jayson Tatum would not be drawn on talk that the Boston Celtics are the new NBA title favourites after clinching their first-round playoffs series against the Atlanta Hawks with Thursday's 118-110 win.

The Celtics clinched the series 4-2, setting up a date in the Eastern Conference Semifinals with the Philadelphia 76ers who swept the Brooklyn Nets 4-0.

The shock exit of the top-seeded Milwaukee Bucks, who boasted the league's best regular-season record at 58-24, to the Miami Heat has opened up the playoffs.

Boston made last year's NBA Finals and finished second in this regular season in the East behind the Bucks with the second-best record in the NBA at 57-25.

"Not looking past nobody," Tatum told reporters when asked about the Celtics being title favourites. "Taking it one game, one series at a time.

"We just had six tough games against the Hawks. Closed it out tonight, now it's time to get some rest and get ready for Philly.

"Not looking past them. It's going to be tough. They've had some time off. It starts with Game 1."

The 76ers benefitted from their sweep, having closed that series out on Sunday, allowing time for MVP candidate Joel Embiid to rest a sprained knee that kept him out of Game 4 against the Nets. The 76ers-Celtics series is due to commence on Monday.

Jaylen Brown, who scored 32 points against the Hawks in Game 6 alongside Tatum's 30, expected a tough test against their old rivals.

"We know they're going to bring the fight," he said. "Philly is a tough environment to win. Their crowd gets involved in the game. It's going to be fun.

"We already know they've got some great players, Joel Embiid, James Harden and company. It's going to be a test again. We've got to be ready to fight and I can't wait for it."

The Celtics were pushed all the way by the Hawks in not only Game 6, but the whole series. Boston needed a final-quarter 11-0 run, which Brown called "winning time", to pull away and punch their ticket into the next round.

"Winning time, I guess," Brown said. "Adrenaline, just that will and perseverance to finish the game. It was close and both teams was exchanging blows, we were both tired.

"And we didn't want to be the team going back home with an 'L.' So we just found a way to win."

Meanwhile, Hawks guard Trae Young was enthused by his side's end to their season after Nate McMillan was axed in February, before an admirable recovery under new coach Quin Snyder.

"Quin is the future," Young said. "I believe with him here, this city's going to win a championship."