ATLANTA -- The Atlanta Hawks were melting down, their 19-point lead over the Boston Celtics long gone. Al Horford wasn't going down like that, though.

Horford scored 24 points, grabbed 11 rebounds and made multiple hustle plays down the stretch, allowing Atlanta to escape with a 102-101 win Saturday in Game 1 of an Eastern Conference playoffs series that is expected to be tight.

After trailing by as many as 19 in the first, Boston's Avery Bradley and Marcus Smart sparked a second-half rally. It was the second straight improbable comeback for the Celtics, who stormed back from 26 down in a win over the Miami Heat in the final game of the regular season. Boston nearly did it again Saturday.

Isaiah Thomas scored 19 points, and Bradley scored 18 points, before suffering a lower leg injury midway through the fourth quarter. He had to be helped off the floor and taken back to the locker room. Bradley did not return.

Smart hit a pair of 3-pointers in the fourth quarter, the second tying the game, 80-80 with 7:30 to play. Jae Crowder followed with a go-ahead 3-pointer that gave the Celtics their first lead of the game with 6:50 to play.

Jeff Teague made three of four free throws in the 15 seconds to secure the win for the Hawks.

Horford came up huge for Atlanta, though. He had an assist to Kent Bazemore, while sitting on the floor and then hustled down an offensive rebound off his own miss that led to two free throws in the final minutes.

Bazemore had a big game with 23 points and eight rebounds, while Teague finished with 20 points and 12 assists.

After scoring 34 points in the first half and trailing by as many as 19, Boston scored 31 points in third quarter to get back into the game. The Celtics scored 34 in the entire first half. Atlanta led by seven, 72-65, entering the fourth quarter.

Game 2 is Tuesday in Atlanta.

Boston and Atlanta ended the regular season in opposite fashions. The Hawks lost Wednesday at Washington to a Wizards team without John Wall. On the same night, the Celtics came from 26 down to beat the Heat. They nearly did again Saturday.

Boston opened the third quarter with an 11-3 run that forced an early Atlanta timeout. Thomas' second 3-pointer of the quarter trimmed the deficit to six, 62-56. Smart finished with 15 points.

Neither team is expected to be able to challenge the Cavaliers in the next round, which makes the Hawks' loss to an undermanned Wizards squad all the more egregious. If the Hawks would have handled the Wizards, they would have earned the third seed and been on the opposite side of the bracket from Cleveland. That misstep in D.C. cost Atlanta a spot on the opposite of the bracket from LeBron James and company, which looks even better with Indiana knocking off No. 2-seed Toronto in Game of 1 of their series.

But if the Hawks were deflated, they certainly didn't show it Game 1 opener of a series expected to be tight. They dominated the first half on both ends of the floor. Offensively, they were aggressive attacking the rim, outscoring Boston 26-8 in the paint.

The Celtics shot 23.1 percent from the floor including 2 of 16 on 3-pointers. The Hawks 51-34 at halftime and appeared to be in command. They weren't, but thanks to Horford and Teague, they had enough to survive a Game 1 thriller.

NOTES: Atlanta F Paul Millsap was named Eastern Conference Player of the Week for games played April 4-10. He averaged 19.0 points and led the league in both rebounds (15.7) and blocks (4.33) during a three-game stretch. ... Atlanta G Tim Hardaway was considered a game-time decision for Game 1 after suffering a strained hamstring in Wednesday's loss to Washington. Hardaway, who emerged as a key contributor off the bench for Atlanta in the final months of the season, did dress out and participate in warmups. ... Boston PG Isaiah Thomas was one of three players (James Harden and Russell Westbrook) with at least 500 free throw attempts and 500 assists, per NBA.com. ... Boston and Atlanta finished with identical 48-34 records, along with the Miami Heat and Charlotte Hornets. The Heat, the only division winner out of the four teams, were granted the No. 3 seed. The Hawks had the best combined record against the Celtics and Hornets and received the No. 4 seed. Boston is No. 5 and the Hornets No. 6. ... Atlanta won three of four against Boston this season, including a 118-107 come-from-behind win on April 9 in Atlanta.