The Philadelphia 76ers were unable to flip on the second-round switch as they suffered a 128-124 home loss to the Atalanta Hawks in Game 1 of their NBA play-offs series.
Trae Young got the Hawks off to a flyer and finished the win with a lob to John Collins for a one-handed jam.
Collins punched the air in celebration as Atlanta took a moment to exhale after a hefty lead was nearly squandered.
Young scored 25 of his 35 points in the first half as Atlanta shook off Joel Embiid and a hostile crowd to take the lead in the best-of-seven match-up in the the Eastern Conference semifinal opener.
Embiid returned from a one-game absence with a cartilage tear in his right knee to finish with 39 points, nine rebounds, and three blocks.
Tobias Harris had 20 points and 10 rebounds while Ben Simmons scored 17 points but again struggled from the free-throw line, going 3 for 10.
Young and the Hawks had the Sixers down for the count from the jump and led by as many as 26 points.
The Sixers - playing in front of their biggest crowd of the season at 18,624 - refused to easily cede home court and Embiid scored consecutive baskets that brought them within three with 1:01 left.
Bogdan Bogdanovic, who missed all three games in the season series against the 76ers with a knee injury, steadied the Hawks when he buried a 3 that gave them needed breathing room.
For all the pre-game focus on Embiid, Simmons and the top-seeded Sixers, Young was the can't-miss player - as Atlanta made 14 of their first 18 shots.
The Hawks used a 17-0 run in the first half - they hit 20 3s overall.
"They hit us in the mouth to start the game," 76ers coach Doc Rivers said.
Danny Green could not hang as the primary defender on Young instead of Simmons, an NBA defensive player of the year candidate.
Simmons said he wanted his shot for a full 40 minutes on Young and the Hawks expected a shift in strategy for Game 2.
In the Western Conference, 28 points from Kawhi Leonard led the Los Angeles Clippers to a 126-111 win over the Dallas Mavericks to secure their first-round series 4-3.
Playing in front of a small but noisy mix of masked fans and cardboard cutouts, the Clippers did what neither team had been able to pull off in the first six games - win at home.
It was the first time in NBA history the road team won the first six games of a post-season series.
The fourth-seeded Clippers advance to face the top-seeded Utah Jazz, with Game 1 on Tuesday night in Salt Lake City.
Luka Doncic had 46 points, 14 assists and seven rebounds to lead the fifth-seeded Mavs, who have yet to win a play-off series since capturing the NBA championship in 2011.