ATLANTA — LeBron James and the Cleveland Cavaliers tried to put the Atlanta Hawks away in the first half, building a commanding 21-point lead in the second quarter, but ended up needing overtime to get the job done.

James finished with 29 points, 16 rebounds and nine assists and Kyrie Irving hit some big free throws in overtime to lead the Cavaliers past the Hawks 110-108 on Friday night at Philips Arena.

It’s the sixth straight win for the Cavaliers over the Hawks, including last season’s four-game sweep in the Eastern Conference finals.

The score was tied 96-96 with 29 seconds to play. James missed a fadeaway jumper from the baseline, giving the ball back to Atlanta with 4.9 seconds left. But the Hawks failed to get a shot off on their last possession of regulation.

Irving made five of six free throws in the final 30 seconds of overtime to help fend off the Hawks. Atlanta forward Al Horford missed a potential winning 3-pointer at the buzzer.

Cleveland coach Tyronn Lue called it a “signature win” for the Cavs.

“I think (the game) meant more to the guys because of the way we did it,” Lue said. “They came back and took the lead after we had a big lead. For us to stay with it and continue to push through and continue to keep fighting and keep grinding. I think as a team it’s a signature win for us.”

The first half was utter domination. The Cavaliers withstood an early spurt by the Hawks before taking complete control. Cleveland outrebounded the Hawks 29-20 in the first half and led by as many as 21 points. Atlanta shot a dismal 30.2 percent (13 of 43) from the field.

James bulled through undersized Hawks defenders for 14 first-half points. He threw down a vicious, one-handed dunk on the break that put the Cavaliers ahead 55-34 with two minutes to go before halftime.

At that point, the Hawks looked cooked. Even the team’s Twitter account acknowledged the situation with a tweet saying, “Not ideal.” But they weren’t done.

“The toughness and the competitiveness that we had to have from everybody just wasn’t where it needed to be in the first half,” Atlanta coach Mike Budenholzer said.

That changed in the second half. Atlanta opened the third quarter with a 21-6 run that featured two 3-pointers from Kyle Korver and three from Paul Millsap that put the Hawks up 62-61 with five minutes left in the quarter.

Cleveland regrouped, though, and took a 77-71 lead into the fourth quarter. Millsap finished with 29 points and 12 rebounds.

“I think the second half is the kind of physicality and toughness and competitiveness that we need to have from the start of the game to the end of the game,” Budenholzer said.

The Cavs (54-22) stretched the lead to 11 on a layup from Matthew Dellavedova early in the fourth quarter before the Hawks made another push. Jeff Teague hit a layup off a pretty dribble drive and Korver followed with a 3-pointer that gave the Hawks the lead back at 89-88 with four minutes to play.

Teague finished with 28 points and nine assists, and Korver had 14 points, including four 3-pointers.

Kevin Love added 15 points for the Cavaliers, who own a 2 1/2-game lead on second-place Toronto in the Eastern Conference race.

“We have a pretty good schedule left in terms of quality,” Love said. “We play some pretty good teams, especially in the East — teams that are potential matchups that we might play.

“We don’t know what we’re looking at rest-wise, but if we’re suiting up to play, we’re going to lace them up and give it everything we got.”

The Hawks were coming off a loss at Toronto but had been playing their best basketball of the season. They had won nine of 11 and were hoping to show that they could compete with the East’s elite but had no answer for James.

Atlanta (45-32) is 0-5 this season against the Cavaliers and Raptors, the top two teams in the Eastern Conference.

“We feel good about our team,” Korver said. “We feel good about the basketball that we’re playing, and we have a lot of pride. I don’t know what we were down at halftime … it felt like we were down 30. They really just outplayed us, and so Coach got on a few of us at halftime and guys responded.”

NOTES: Cleveland F LeBron James moved past Hall of Famer Dominique Wilkins into 12th place on the NBA’s career scoring list in Thursday’s win over the Brooklyn Nets and into 11th on Friday, passing Oscar Robertson. … The Hawks and Cavs will meet one more time during the regular season on April 11 in Cleveland. … Atlanta has clinched a playoff berth for the ninth straight season, the longest streak in the postseason. … Hip-hop artist T.I. performed at halftime and after the game.