BOSTON — So much for the layoff hurting the Cleveland Cavaliers.

The defending champions, playing their first game since May 7, put on a clinic, leading wire to wire and cruising to a 117-104 blowout of the Boston Celtics in Game 1 of the Eastern Conference finals Wednesday night.

Game 2 is Friday night at TD Garden before the series shifts to Cleveland for Games 3 and 4.

The Cavs toyed with the Celtics from the start, building a 26-point lead in the first half and expanding it to 28 in the third quarter before the Celtics cut it down to 17 at the end of the quarter. Boston rallied some and actually cut the deficit to 11 with the benches cleared in the final minutes.

LeBron James, looking to advance to his seventh straight NBA Finals, led the Cavs with 38 points (15 in the fourth quarter), his seventh consecutive 30-point game. He added nine rebounds and seven assists.

Kevin Love, who hit four 3-pointers in the third quarter, scored a career-playoff-high 32 points and grabbed 12 rebounds, becoming the first Cav other than James with 30 points and 10 rebounds in a playoff game since Brad Daugherty in 1992. Tristan Thompson had 20 points (shooting 7-for-7 from the floor) and nine rebounds, and Kyrie Irving contributed 11 points and six assists.

At one point in the third quarter, the Cavs were 28 of 45 from the floor. They finished the game at 48.1 percent.

Avery Bradley and Jae Crowder led the Celtics with 21 points apiece, while Isaiah Thomas, hounded all night, had 17 points and 10 assists. He was just 7 of 19 from the floor, 2 of 7 from 3-point range.

Boston made 46.6 percent of its field-goal attempts.

Thomas hit a 3-pointer with 2.8 seconds left in the first half, his team’s second trey in 16 first-half attempts. The Celtics finished 12 of 38 (31.6 percent) from long distance, while the Cavs were 11 of 31 (35.5 percent).

The win was the Cavaliers’ 12th in a row in the playoffs (one shy of matching the NBA record, set by the 1988-89 Los Angeles Lakers), dating back to last year’s Finals, while the Celtics’ five-game home playoff winning streak was stopped.

Some third-quarter unpleasantness erupted between Thompson and Boston’s Marcus Smart, whose fiery play kept his team somewhat alive — his flying slam on a rebound with 2.8 seconds left in the third igniting the crowd. The pair were whistled for double fouls on one occasion and came together on other occasions.

NOTES: Cleveland F LeBron James reportedly erased a white board of plays when told Boston F Kelly Olynyk had 26 points in Game 7 against Washington on Monday night. “Seriously?” he said. “We had like two weeks to get ready and now at the last second it turns out Kelly Olynyk has the ability to make shots and get rebounds and stuff? Well, back to the drawing board I guess.” Olynyk scored two points in the final minute and had three rebounds Wednesday. … Boston C Al Horford on the Celtics getting the top pick in the lottery: “That’s big for our franchise. The first time in history — that’s pretty cool.” … Celtics coach Brad Stevens on winning the lottery: “It’s a great opportunity for us.” … Former Red Sox DH David Ortiz was seated next to the Celtics’ bench.