Cleveland Cavaliers vs Boston Celtics Box Score on May 27, 2018

James has reached the NBA Finals in eight straight seasons, including four in a row with Cleveland. Only Bill Russell (10), Tom Heinsohn (nine) and Sam Jones (nine) have made more consecutive appearances in NBA history.

The Cavaliers will play the winner of Monday's Game 7 of the West finals between Houston and Golden State. Cleveland has faced the Warriors in the last three NBA Finals, winning in 2016 and losing in 2015 and 2017.

"We've been counted out for a long time this season," James said postgame on ESPN. "Right around the trade deadline, no matter if we made a trade or not at that point in time, I kind of just switched my mindset on saying, 'Let's get this most out of this season I can.' I'm determined to get the most. I'm trying to squeeze this orange until there's no more juice left.

"This is a heck of an accomplishment for our ballclub -- without our All-Star power forward (Kevin Love), as well, for basically two games. This (Boston) team was undefeated in the postseason at home, and for us to be able to do this, and for me to be able to lead these guys, it's a treat."

James, who entered with an NBA-record Game 7 average of 34.9 points, improved to 6-2 lifetime in Game 7s.

Cleveland coach Tyronn Lue rated James' performance Sunday alongside that in Game 7 of the 2016 NBA Finals as the forward's two best.

"I mean, the bigger the stage, the bigger the player, and he's been doing it for us since we've been here," Lue said. "The great quote from the great Doc Rivers is you always want to go into the Game 7 with the best player, and we have the best player on our team going into a Game 7. I like our chances. And he delivered again."

Jayson Tatum scored 24 points to lead the Celtics, who lost at home for the first time this postseason in 11 games. Al Horford added 17 points and Marcus Morris had a double-double with 14 points and 12 boards.

Boston was denied its first Finals trip since 2010, when it lost to the rival Los Angeles Lakers in seven games.

Jeff Green had 19 points and eight rebounds, JR Smith scored 12 points and Tristan Thompson had 10 points and nine boards for the Cavaliers.

Cleveland won without Love, who missed the game after sustaining a concussion in Game 6. Love has entered the NBA's concussion protocol, and his status for the NBA Finals is uncertain.

Lue said of the Cavs winning without Love: "We told the guys that Kevin wasn't coming back, and they all got together and just huddled up and just came together as one, and coming into tonight, we knew he was going to be out, and we said we want to do this for Kevin.

"It's tough, Kevin wanted to play, to be in a Game 7 situation like this in the Eastern Conference finals, being an All-Star, being our second-best player, and he just wasn't able to go. So he was down, but the guys picked him up, so now he has another chance when we get to the Finals to be ready."

After Cleveland was ahead 76-73 with 4:44 to go, Boston missed its next nine field-goal attempts as the Cavs opened the lead to 86-74 heading into the final seconds.

Green's 3-pointer with 4:56 left in the third quarter put Cleveland up 53-51, the Cavs' first lead since the opening minutes. Cleveland went ahead by as many as five after that before taking a 59-56 lead into the fourth.

Tatum hit a 3-pointer after his driving dunk over James put Boston up 72-71 with 6:04 remaining in the game, but Green answered with another trey at the 5:44 mark, and Cleveland didn't relinquish the lead after that.

Boston was up 43-39 at halftime after leading by as many as 12 in the first half.

Celtics coach Brad Stevens said, "I thought the biggest moment of the game was when we couldn't extend the lead in the second quarter. We were in really good shape, really good shape -- and then we just couldn't quite extend the lead. I thought that added to probably the shooting the rest of the game."

Boston wound up shooting 34.1 percent from the floor, including 17.9 percent from 3-point range (7 of 39). Cleveland made 45.5 percent of its field-goal attempts, including 9 of 35 from beyond the arc (25.7 percent).

James went flying into the stands with less than nine minutes left in the first quarter trying to deflect a full-court pass out of bounds. After slowly getting back on his feet, James shook hands with a fan he knocked over.

Horford said of James' overall performance, "It's one of those things that I've got to tip my hat off to him. As a group, we really fought hard, we did everything we could. We put ourselves in position. We were one or two shots away from being there, and it just wasn't enough."

--Gethin Coolbaugh, Field Level Media