BOSTON » LeBron James scored 31 points and the Cleveland Cavaliers moved one win away from a sweep in their first playoff series in five years with a 103-95 victory over the Boston Celtics on Thursday night.

The scrappy Celtics kept it close, just as they did in the previous two games, and trailed 95-92 after Evan Turner hit a 3-pointer with 2:45 left. But Kevin Love hit two 3-pointers for a 101-93 lead with 26 seconds to go.

Cleveland can complete the sweep of the best-of-seven, first-round series Sunday in Boston. No NBA team has won a series after trailing 3-0.

Turner had 19 points and Avery Bradley added 18 while Isaiah Thomas managed just five points after scoring 22 in the first two games.

Love had 23 points and J.R. Smith added 15 for the Cavaliers.

James went to TD Garden more than an hour before Thursday’s shootaround to work on his game, despite having scored 50 points in the first two.

It was his first postseason game in Boston since Game 6 of the 2012 Eastern Conference finals when he was with Miami. He had 45 points and 15 rebounds in that game to avoid elimination. The Heat won Game 7 at home then beat Oklahoma City for James’ first NBA title.

On Thursday he was booed nearly every time he touched the ball in the first half. The Celtics led 48-44 before the Cavaliers closed with a 12-0 run for a 56-44 lead. In the last 40 seconds, James had six points and a steal.

Boston tied it at 56 by scoring the first eight points of the third quarter. Then Cleveland went on another spurt and took a 77-66 lead on a 3-pointer by Kyrie Irving with just under 4 minutes left in the period.

The Cavaliers led 84-76 after three quarters before James opened the fourth by scoring Cleveland’s first seven points for an 89-78 lead then fed Tristan Thompson with an alley-oop pass.

Cleveland is in its first playoff series since 2010 when it lost the Eastern Conference semifinals in six games to Boston. Two months later, James left for the Heat and led them to the NBA Finals in all four of his seasons, winning two championships before returning to the Cavaliers this season.

James finished with 11 rebounds and Love had nine.

TIP-INS

Cavaliers: Love had nine points in the opening quarter after totaling just three in the first 12 minutes of the first two games. … Irving didn’t make his first field goal until he hit a 3-pointer with 6:27 left in the third quarter, giving Cleveland a 70-66 lead.

Celtics: Brad Stevens coached his first NBA home playoff game but watched as a fan in the 2008 playoffs in the building. … Boston made six of its first seven shots in the third quarter.

HARD KNOCKS

The Celtics played more physically in the first half than they did in the first two games. Jonas Jerebko knocked down Irving on a hard foul and Smith received a technical while players milled around. And in the final minute, Turner received a flagrant foul against James, who then made two free throws and a jumper on the game’s next possession.