James made his first nine shots — one an arena-rattling powerhouse dunk — and the Cavs shot 67 percent from the field in the first half while improving to 9-0 this postseason. Cleveland is the first team to start the playoffs with nine straight wins since San Antonio reeled off 10 in a row in 2012.

But unlike their second-round series when they made 77 3-pointers and swept Atlanta, the Cavs did most of their damage from close range. Cleveland made just 7 of 20 3-point attempts.

DeMar DeRozan scored 18 points and Bismack Biyombo added 12 for Toronto.

Kyle Lowry, who scored 35 points in the Raptors’ Game 7 win over Miami, was held to just eight as he and the Raptors were roughed up in their first appearance in the conference finals.

Unless Toronto figures some things out quickly, these Raptors will be extinct, too.

Game 2 is Thursday night.

Cleveland figured to have some rust following a nine-day break since ousting the Hawks. But not only did the Cavs look refreshed, they looked better than before, taking their game to another level.

And James, as is almost always the case, led the charge. He finished 11 of 13 from the field and added six rebounds and four assists in just 28 minutes. James spent the final quarter on the bench cheering on Cleveland’s reserves, who finished off the club’s most lopsided postseason victory.

The Cavs outscored the Raptors 33-16 in the second quarter when James personally welcomed Canada’s NBA franchise to the East’s final round with a devastating dunk.

Driving baseline past DeMarre Carroll, James cut across the lane and hammered home a right-handed windmill. He celebrated the slam by tilting his head, backpedaling and letting out a primal scream along with 20,000 fans.

The impressive bucket capped a 20-2 spurt for the Cavs, whose swarming defense was making life miserable for Lowry and his teammates. Toronto didn’t get its first field goal until 6:28 remained in the quarter. The Raptors regrouped for a moment and closed within 12 before the Cavs decided enough was enough and closed the half with a 12-4 flurry to go up 66-44.

The Raptors came in as overwhelming underdogs, but coach Dwane Casey wasn’t worried about the stage being too big or his team fearing the Cavs.

“They’re a very good team,” he said. “They’re at the top of their game. But we’re both here for a reason. Nobody gives us a chance. So there shouldn’t be any pressure on our guys.”

The Cavs aren’t feeling any either.

TIP-INS

Raptors: Didn’t have center Jonas Valanciunas because of a sprained right ankle. He’s doubtful for Game 2. … Casey nearly hired Cavs coach Tyronn Lue two years ago before he signed with the Cavaliers as David Blatt’s top assistant. “We talked, and he made a good decision,” Casey said. “He’s a good young coach, a good person.”… On the same night as its Eastern finals debut, Toronto also secured the No. 9 overall pick in the NBA draft lottery. … Played their 15th postseason game in a 31-day span, compared to nine for Cleveland.

Cavaliers: Cleveland’s nine-game winning streak is the longest for any Cleveland team in postseason history. The Cavs also won nine straight in 2009. … Lue is flattered that Lowry calls him a “father figure.” The two became tight when Toronto’s guard entered the league. “When he first came in, he said that he wanted to be like Tyronn Lue,” Lue said with a chuckle. “He wanted to compare himself to me. I was like, ‘Well, you can be much better than me.’ He’s very well surpassed me as a player.”… James became the first player to appear in 100 postseason games for the Cavs. He played in 87 with Miami. . James has won 17 straight Eastern Conference playoff series.