ATLANTA — Right about the time Kevin Love ran off the floor holding his shoulder and Kyrie Irving began dragging his foot up and down the court, the Cavaliers evolved from an offensive juggernaut into a defensive force.

After a slow start Wednesday, that defense and J.R. Smith’s red-hot shooting carried the Cavaliers to a 97-89 victory over the Atlanta Hawks in Game 1 of the Eastern Conference finals. The Cavs immediately snatched home-court advantage from the Hawks by winning their first Game 1 on the road in franchise history. They began the night 0-14 in road openers and now can take a commanding lead in this series with Game 2 set for Friday at Philips Arena.

Smith set a postseason career-high with 28 points, LeBron James had 31 points, eight rebounds and six assists, including 14 points in the second quarter, and the Cavs yet again won on a night they received little from Irving.

Irving scored 10 points, shot 4-of-10 and played just three of the game’s final 18 minutes after aggravating his left knee injury in the third quarter. Just as Matthew Dellavedova replaced Irving’s punch in the closeout game against the Bulls, Wednesday it was Smith’s turn to do it to the Hawks.

He made 8-of-12 3-pointers, helped patch a defense that struggled early and made big shots throughout the second half.

“Once I start shooting, whether I make or miss, everybody tells me to keep shooting,” Smith said. “It’s a great situation.”

The Cavs opened an 82-67 lead with 10:27 left, their largest of the night at the time, on a stepback 3-pointer by Smith followed by a lob from Smith to Tristan Thompson.

James’ basket gave the Cavs an 89-74 lead with 7:01 left, but they missed their next eight shots and the offense grinded into an isolation game, turning the ball over three times and going more than six minutes without a basket to allow the Hawks to climb back in it.

“In the fourth quarter I played way too much isolation basketball,” James said. “I will do a better job. It starts with me.”

James’ dunk down the middle of the Hawks’ defense pushed the lead to 93-87 in the final minute, Thompson grabbed his 10th rebound of the game at the other end and the Cavs made free throws to close out the win.

Thompson was a concern for the Hawks entering the series and prominent on their scouting reports. A few Hawks players mentioned prior to the game the importance of keeping Thompson off the glass, which became apparent in the first quarter when he had three offensive rebounds in the game’s opening minutes.

Thompson finished with 14 points and 10 rebounds, Timofey Mozgov had 10 points and 11 rebounds and the Cavs outrebounded the Hawks 49-37.

The Hawks’ biggest lead was 24-15 late in the first quarter when the Cavs committed six turnovers and Jeff Teague tormented their guards.