BOSTON -- The only thing that seemed to roar louder than the TD Garden crowd was Marcus Morris.
Boston's brash forward had spilled beyond the baseline while finishing a third-quarter layup through the contact of Tristan Thompson and then, sitting at the feet of Boston Celtics co-owner Wyc Grousbeck in a game where the score would soon be tied, Morris turned toward Thompson, who was lying next to him, and repeatedly screamed directly in his face.
The sequence lit a fuse that had been dampened by the first-quarter offensive barrage of a clearly motivated LeBron James. But as these fearless and relentless Celtics had done so often this season, Boston calmly overcame a double-digit deficit and, fueled by its third-quarter surge, emerged with a gritty 107-94 triumph over the Cleveland Cavaliers in Tuesday's Game 2 of the Eastern Conference finals.
The Celtics will have three days to sit on a 2-0 series lead. Game 3 is Saturday in Cleveland.
NBA teams that win the first two games of a best-of-seven series have gone on to win their series 95 percent of the time.
James has trailed 2-0 six times in his career and has come back to win twice -- the 2016 NBA Finals against the Warriors and the 2007 conference finals against the Pistons, per ESPN Stats & Information research.
Jaylen Brown scored a team-high 23 points, and Al Horford had 15 points and 10 rebounds. James finished with a triple-double, scoring 42 points on 16-of-29 shooting, grabbing 10 rebounds and dishing out 12 assists.
Moments after Morris' exultation, Marcus Smart, whose hustle and energy proved vital throughout the game, hit a go-ahead 3-pointer. Feeding off the building momentum, Brown's hustle prevented Thompson from chasing down an offensive rebound, and Terry Rozier broke out the other way to throw down an emphatic tomahawk jam before James could close on a potential chasedown.
The Celtics improved to 9-0 this postseason at TD Garden, where they've routinely fed off the energy of a crowd that keeps upping its ante. Boston's third-quarter surge produced decibel levels on par with that seen in the Celtics' Game 2 win over the Philadelphia 76ers in which the team overcame a 22-point deficit and later raved about the noise inside the building.
Early on, it seemed as if this night would belong to James and the Cavaliers. Limited to 15 points in Cleveland's Game 1 loss, James needed just 7 minutes, 34 seconds to eclipse his scoring output from Sunday's opener. His first-quarter barrage crescendoed with an utterly absurd, late-clock fadeaway 3-pointer in front of the Cavaliers bench that helped Cleveland open as much as an 11-point first-half lead.
But it might have been the hustle of Smart near the end of the first half that gave the Celtics life after the Cavaliers led by double digits with under four minutes to play in the second quarter.
Smart's steal and feed of Morris with 17.2 seconds left in the half helped Boston narrow its deficit to seven and gave the team confidence heading into the intermission.
Rozier took over in the third quarter, scoring 14 points in the frame (his playoff career high for a single quarter), and helping the Celtics outscore the Cavs 36-22 overall, which swung the game in Boston's favor.