Boston, MA (Sports Network) - Kevin Garnett scored 28 points, including the go-ahead layup with 21.4 seconds left, and the Celtics put a defensive blanket on LeBron James, holding the Cavaliers superstar to only two field goals, as Boston edged Cleveland, 76-72, in the opener of their Eastern Conference semifinal series.

It was an uncharacteristic contest for a few standout players, but most notable was James' horrific 2-of-18 night from the field. He totaled 12 points, nine rebounds and nine assists, but had 10 of Cleveland's 18 turnovers.

Boston's Paul Pierce and Ray Allen combined for just four points on 2-of-18 shooting. Allen was held scoreless for the first time since Feb. 26, 1997.

"This was just two heavyweights body punching," Garnett said. "There wasn't any finesse, weren't any jabs. It was all body punches. It was just an all-out beat-down defensive fight."

Sam Cassell scored 10 of his 13 points in the fourth quarter for the top- seeded Celtics, who were pushed to seven games by Atlanta in the first round and then committed 23 turnovers Tuesday night.

"We didn't have a great rhythm tonight," Allen said. "It seemed like we were unsettled on offense and we were rushing through a lot of things and we got bad shots and turned over the ball as a result of it. We had to win the game on the defensive end."

Rajon Rondo totaled 15 points and Kendrick Perkins pulled down 12 rebounds, while Garnett had eight boards.

Zydrunas Ilgauskas had 22 points and 12 rebounds for the Cavs, who also got 13 points from Wally Szczerbiak. Cleveland shot just 30.7 percent from the field.

"We missed a lot of good shots," Ilgauskas said. "Also, turnovers killed us. On the road, with so many turnovers, it's hard to win close games."

Game 2 is Thursday night, again at TD Banknorth Garden.

"We've been in series like this before against good defensive teams," Cavs coach Mike Brown said. "We've just got to make sure we continue trying to get stops and execute for 48 minutes and if we do we give ourselves a chance to win, especially on the road."

Ilgauskas' jumper, off a feed from James, gave the Cavs a 70-68 lead with 1 1/2 minutes left, but Garnett came back with a jumper from the left side 13 seconds later.

James then missed a driving layup, and Cassell was fouled after getting the loose ball and hit both free throws with 52.8 seconds left.

However, Ilgauskas tipped in a missed layup from James with 39 seconds to go for another tie before Garnett drove on Joe Smith in the lane for a layup and the 74-72 lead.

"I noticed they were trapping from different positions," Garnett said. "I saw a lane and was just aggressive, took my time, got my head up. It was a good shot."

James then missed on a drive to the hoop. James Posey, who seemingly tried to reach in and foul James because Boston had one to give, got the rebound and nailed two free throws with 8.5 seconds remaining. James was off the mark on a three-ball in the closing seconds.

"The only thing we didn't execute was the foul to give and it may have worked out in our favor," Boston coach Doc Rivers said. "I think LeBron may have thought driving he was going to get fouled. It was really falling into our hands and we still let them get to the bucket."

James had averaged 34.5 points over his previous 10 games with Boston, but his lone field goals in Game 1 came 1:25 into the game and with 5:34 remaining in the fourth quarter. James had just two points in the second half.

"We just tried to direct him toward where the help is," Pierce said. "I think we just tried to keep him off the fast break, easy opportunities."

The Cavs were just 4-of-19 shooting in the opening quarter and trailed 25-15, this despite scoring the game's first five points. Garnett had 12 points in the period. A three-ball from Posey in the right corner in the final second provided the 10-point margin.

Garnett and Rondo combined for 31 of Boston's points in the opening 24 minutes, while Pierce and Allen were held to a combined two on 1-of-8 shooting. Meanwhile, Garnett and Rondo were 12-of-15 from the floor.

Boston's defense swarmed every time James touched the ball. He nearly scored on a breakaway layup, but Allen got his hands on the ball and Cassell grabbed James' jersey from behind and was called for a flagrant foul with 5:35 left.

Cleveland trailed by as many as 12 in the second quarter and got as close as two. James' pass to Ilgauskas resulted in a layup in the waning moments, but Rondo crashed into James near half-court with 0.2 seconds left. It resulted in two made free throws to provide the 41-37 halftime margin.

A jam and layup from Garnett expanded the lead to 45-37 less than a minute into the third, but Ilgauskas, who had eight third-quarter points, keyed a big run for the Cavs. Cleveland scored the ensuing 14 points with Szczerbiak's three-ball capping the flurry.

The Celtics were held without a point for nearly a seven-minute stretch, but still held a 53-52 lead going into the fourth.

Posey and Cassell each nailed three-pointers, sandwiched around a long- distance shot from Cleveland's Sasha Pavlovic to start the fourth. Cassell nailed a three and a pullup jumper during a seven-point Boston run for a 66-60 lead, but Szczerbiak responded with a three.

Daniel Gibson's three for the defending Eastern Conference champions tied the score at 68 with 2:18 remaining.