Celtics Kendrick Perkins (43) attempts a shot over Detroit Pistons Chauncey Billups (1) during third quarter of Game 5 of their NBA Eastern Conference Final basketball playoff series in Boston, Massachusetts May 28, 2008. (Xinhua/Reuters Photo)

Kevin Garnett scored 33 points and Ray Allen chipped in 29 as the Boston Celtics defeated the Detroit Pistons 106-102 on Wednesday in Game 5 of the National Basketball Association semifinals.

Kendrick Perkins scored 18 points and had 16 rebounds and Paul Pierce added 16 points for the Celtics, who received all but three points from its starting five in taking a 3-2 lead in the best-of-seven Eastern Conference series.

"It was electric," Allen said. "We are facing a team that has been in these situations before. We are growing every night.

"It was a matter of me getting in rhythm."

The Celtics, who almost gave away a 15-point lead in the fourth in front of a crowd of 18,624, can advance to the NBA Finals Friday with a win in Game 6 at Detroit.

"We got to have great focus in our next game," Celtics coach Doc Rivers said. "They have won titles so we just have to go in there and make sure we play our game and can't get caught up in anything they are doing.

"They were grabbing, holding and bumping tonight and it didn't affect us."

Detroit Pistons Richard Hamilton reacts to an injury during fourth quarter of Game 5 of their NBA Eastern Conference Final basketball playoff series in Boston, Massachusetts May 28, 2008. (Xinhua/Reuters Photo)

Guards Chauncey Billups and Richard Hamilton led Detroit with 26 and 25 points.