BOSTON — A fourth straight NBA Finals matchup between the Cleveland Cavaliers and Golden State Warriors doesn’t look like a safe bet anymore.

The Boston Celtics took a 2-0 lead in the Eastern Conference finals with a 107-94 win over the Cavs on Tuesday night at TD Garden.

The C’s trailed by as many as 11 points in the first half, but a strong second half in which they outscored Cleveland 59-39 paced them to victory.

LeBron James scored 21 points in the first quarter and finished with a game-high 42, but it wasn’t enough to beat a balanced scoring output from the Celtics.

Jaylen Brown led Boston with 23 points. He was one of six double-digit scorers for the Celtics.

Here’s how Game 2 unfolded:

PG: Terry Rozier
SG: Jaylen Brown
SF: Jayson Tatum
PF: Marcus Morris
C: Al Horford

Tristan Thompson started over Kyle Korver to give the Cavs more rim protection, as well as better defense against Horford.

The Cavs jumped out to a 19-13 lead behind 14 early points from James, including three 3-pointers. James scored his 16th point 8:35 into the game, besting his Game 1 total of 15 points.

Despite an incredible 21-point quarter (James’ highest-scoring quarter in a playoff game) from No. 23, the Celtics still only trailed 27-23 at the end of the first quarter. No other Cavs player scored more than two points in the opening 12 minutes.

Brown paced the Celtics with 14 first-quarter points on 5-for-6 shooting (3-for-5 on 3-pointers). Horford chipped in five points.

Both teams shot 45 percent from the floor in the opening quarter.

Tatum kept the Celtics close in the first half of the second quarter by scoring eight early points in the frame. Whether it was attacking the basket or pulling up from mid-range, the rookie forward was on fire.

The Cavs’ defense picked up and the Celtics went cold from the floor as a result, allowing Cleveland to build a 47-36 advantage late in the second quarter.

James left briefly after taking an apparent hit up high from Tatum along the baseline, but he re-entered the game after just a few minutes of real time. Cleveland’s official diagnosis of the injury was a neck strain.

The Celtics trimmed the lead a little bit, but the Cavs still went into halftime up 55-48. James led the Cavaliers with 25 first-half points, but he did miss five of his eight free throw attempts.

Kyle Korver added 11 off the bench on 4-for-5 shooting.

Brown paced Boston with 16 points. He was the only Celtic in double figures at halftime. Tatum poured in nine but also picked up three fouls.

Cleveland shot 51.2 percent in the first half, besting Boston’s mark of 43.2 percent. The Cavs had a 6-3 edge in offensive rebounds, which led to some easy second-chance baskets.

The Celtics cut the Cavs lead to 61-55 when Brown attacked James off the dribble and scored at the rim, forcing Cleveland to take a timeout.

The Celtics tied the score at 66, led by eight points from Rozier. Marcus Smart gave the Celtics a 72-71 lead with a 3-pointer, then a steal and dunk on the ensuing Cavs possession forced Cleveland to take a timeout trailing 74-71 after a 13-5 run by the C’s.

A 3-pointer by Aron Baynes gave the C’s their largest lead of the night at 79-74 with 2:39 left in the quarter.

Rozier hit another 3-pointer to put the Celtics up 84-77 entering the fourth quarter. Boston closed the quarter on a 33-16 run.

Brown (20 points) and Rozier (16) were the high scores for the C’s through three quarters. James (32) and Kevin Love (20) led the way for Cleveland.

The Celtics took advantage of a weird Cavs lineup to begin the fourth quarter and pushed their lead to 88-77, forcing Cavaliers coach Ty Lue to burn another timeout after 46 seconds of action.

The Celtics went up 89-80 after a free throw by Brown, putting the Cavs in the penalty with 8:21 remaining.

James trimmed Boston’s advantage to 95-89 with half a quarter to play, but Celtics free throws pushed their lead back to eight at 97-89.

Tempers flares when JR Smith shoved Horford as he was midair. Smart came over to stick up for his teammate and exchanged shoves with Smith. Smith was assessed a flagrant 1 foul for his actions.

The Celtics closed out the game with a few defensive stops over the final few minutes.

Sometimes, James is just too good.

Game 3 of the series is Saturday in Cleveland at 8:30 p.m. ET.

Thumbnail photo via Bob DeChiara/USA TODAY Sports