Updated

Boston, MA (SportsNetwork.com) - LeBron James and the Cavaliers finally shook the Celtics, building a series lead no NBA team has ever squandered.

Kevin Love helped them do it, hitting a couple of late 3-pointers in his best game of the series so far.

James had 31 points and 11 rebounds and No. 2-seeded Cleveland beat Boston 103-95 on Thursday night for a 3-0 lead in their first-round set.

Love, playing in the postseason for the first time, added 23 points and nine rebounds. He made six 3-pointers, including two in the final 2 1/2 minutes as the Celtics tried to scrape their way back into it.

He had 12 points in the first half after scoring 13 in all of Game 2, which the Cavs won 99-91 on Tuesday.

"Kevin has been great overall," said Cavs coach David Blatt. "He didn't score as much in the second game as he did tonight, but he's been engaged. I haven't seen any nervousness and discomfort since the series began."

J.R. Smith chipped in 15 points, Kyrie Irving scored 13 and Tristan Thompson had 12 for the Cavs.

The Celtics will also host Game 4 on Sunday, but no NBA team has ever won a series after trailing 3-0.

Evan Turner led them with 19 points, Avery Bradley scored 18 and Jae Crowder added 16 off the bench.

The Cavs led most of the game -- including the entire second half -- but spent nearly all of it trying to shake the Celtics for good.

After James' fastbreak dunk gave them a seven-point lead in the third quarter, Boston cut it to one. Cleveland extended it to 11 and the Celtics scored eight of the next 10 points.

It was an eight-point margin going into the fourth and grew to 11 again, but still the Celtics wouldn't go away. Turner's open straightaway 3-pointer got them within three, but Love was even more wide-open at the other end, taking his time to line up a 3 he made from the left wing. Later, his sixth 3 of the game stretched the lead to eight with just 26.7 seconds remaining.

"We have to play batter basketball," said Brad Stevens, the 38-year-old Boston coach who picked up a couple of first-place votes on ballots for NBA Coach of the Year. "I don't mean to sound that general and I'm sorry I do, but we have to play better basketball at both ends."

The Cavs will try to sweep a playoff series first the first time since running the table against Detroit and Atlanta in 2009. The Celtics haven't been swept since falling to Indiana in the first round in 2004.

Blatt, a Boston-area native who grew up a Celtics fan, broke into a Beantown accent during his postgame news conference but was serious about how tough it's been to go up 3-0.

"This was not an easy game and honestly, none of the three games have been easy," Blatt said. "They have been playing us tough, as it should be in the playoffs."

Love's 3-pointer made it 7-2 after 2 1/2 minutes and the Cavs led by as many as six in the first quarter.

They pushed it to nine in the second, but the Celtics rallied. Tyler Zeller had five points in a 9-0 run later in the quarter and Boston took its first lead of the game on a goaltending call against Timofey Mozgov.

The Cavs scored the final nine points of the half for a 56-48 lead. James had the last six, including two after Turner was called for a flagrant foul for grabbing James around the chest and shoulder to prevent a dunk or a layup.

Game Notes

The Celtics outscored the Cavs 48-28 in the paint ... Boston had 15 turnovers, leading to 20 Cleveland points ... Cleveland's biggest lead was 11 ... Smith received a technical foul during a scrum midway through the second quarter.