Kyle Korver had 14 points and Kevin Love added 13 with 14 rebounds for the Cavaliers, who lost the first two games of the series on the road in Boston. George Hill totaled 13 points, JR Smith had 11 and Tristan Thompson scored 10.
"I have a huge responsibility for this team," James told the ABC broadcast after the game. "I have to score, I have to rebound and defend, make sure guys get involved, and I'm OK with that. I'm absolutely OK with that.
"I also have to inspire my teammates to be better. They answered the call tonight, and they need to answer the call at another time (in Game 4) on Monday."
Jayson Tatum scored 18 points to lead Boston. Terry Rozier contributed 13 points and both Jaylen Brown and Greg Monroe finished with 10 for the Celtics, who dropped to 1-5 on the road this postseason.
Boston, which is a perfect 9-0 at home in the playoffs, was trying to become the third team ever to take a 3-0 series lead against a James-led squad, which has only been accomplished by the 2007 San Antonio Spurs and the 2017 Golden State Warriors.
"I don't want to take away from their performance by talking about us," Celtics coach Brad Stevens said. "They deserve all the credit. They deserve to be talked about, because they played great."
Cleveland shot 48.7 percent (37 of 76) for the game and 50 percent (17 of 34) from 3-point range while outrebounding the visitors 45-34. Boston was limited to 39.2 percent (29 of 74) shooting, going 6-for-22 (27.3 percent) from 3.
The Cavaliers led 61-41 at halftime.
Boston, which never led, fell behind by as many as 30 after that. Cleveland's lead never shrank below 19 in the second half.
Terry Rozier's layup with 9:26 left in the first quarter had the Celtics within three, but James' layup at the 9:03 mark sparked a 13-0 run that put Cleveland ahead 20-4. The Cavaliers were up 32-17 after the first.
James improved to 13-0 in the playoffs when his team has led by 15 or more after one quarter.
--Field Level Media
Boston | Cleveland | |
Jayson Tatum 18 | Scoring | LeBron James 27 |
Marcus Smart 6 | Assists | LeBron James 12 |
Al Horford 7 | Rebounds | Kevin Love 14 |
Jayson Tatum 6 | Free Throws Made | LeBron James 8 |
Marcus Smart 2 | Steals | Larry Nance Jr. 3 |
Aron Baynes 2 | Blocks | LeBron James 2 |
Team | Points | FG% | 3PM-3PA | FTM-FTA | Assists | Rebounds | Blocks | Steals | Turnovers |
Boston | 86 | 39.2 | 6-22 | 22-28 | 16 | 34 | 4 | 4 | 15 |
Cleveland | 116 | 48.7 | 17-34 | 25-30 | 23 | 45 | 3 | 9 | 15 |