Despite a 10-day hiatus since sweeping their way past the Toronto Raptors in the second round of the 2017 NBA Playoffs, the Cleveland Cavaliers showed little signs of rust against the Boston Celtics in Game 1 of the Eastern Conference Finals at TD Garden Wednesday night.

The Cavaliers used the momentum from a strong start in the first half to come out with a 117-104 victory over the Celtics, who were coming off of a one-day break after a tough seven-game series with the Washington Wizards in the second round.

“We wanted to get off to a great start,” Cavaliers Tyronn Lue said. “This crowd is unbelievable, so we wanted to come out early and try to take the crowd out.”

The Cavaliers accomplished that by building a 30-19 lead over the Celtics after the first quarter.

Despite missing all five of their looks from three-point range, the Cavaliers knocked down 13 of their 17 looks from inside the arc, including a seven-of-eight showing from small forward LeBron James, who scored a game-high 15 points in the first quarter.

Additionally, the Cavaliers held a 15-4 edge in rebounds, including a 5-2 advantage on the offensive glass.

The Cavaliers dominated play on both sides of the floor, and despite a buzzer-beating three-pointer from Celtics point guard Isaiah Thomas, took a 61-39 lead into the locker room at halftime.

The Cavaliers started the second quarter on a 6-1 run, and their 36-20 lead forced the Celtics into their second timeout of the game.

Although the Celtics responded with five straight points out of the break, the Cavaliers went back to work and put together a 12-0 run over the next three-plus minutes.

Reserve guard Iman Shumpert got the run started when he caught a pass from James and buried a three-pointer from 26 feet away. Then, forward Kevin Love scored five of the Cavaliers’ next seven points when he converted a pair of free throws and followed up with a three-pointer from the left wing.

Center Tristan Thompson was rewarded for the extra effort on Cleveland’s next possession as he rolled to the hoop, caught an alley-oop from point guard Kyrie Irving and threw down a thunderous dunk that forced the Celtics into a full timeout.

James scored the Cavaliers’ final eight points of the half, twice on jumpers after posting up on the left low block, and then, after knocking down a pair of free throws and missing a layup, he finished off a drive with a basket in the waning seconds of the half.

“I thought we did a good job of that,” Lue said of the strong half. “I thought it started with our defense. I thought defensively, we were really active, really rotating, doing a good job. When we're playing defense like that and we're able to get out in transition and run, we're tough to beat.

“That was Game 1, but we did a good job of coming out, throwing the first punch.”