AUBURN HILLS, MICH. ? It was appropriate the Boston Celtics had to beat an opponent from their most recent glory years to get back to the Eastern Conference finals.

Paul Pierce scored 18 points as part of a balanced attack as the Celtics defeated Detroit 90-81 Tuesday night to advance to the conference finals for the first time since 1988.

Detroit's Jerry Stackhouse passes over Boston's Paul Pierce. The Celtics defeated the Pistons, 90-81, Tuesday night in Auburn Hills, Mich.

The last time Boston got this far, they lost to the Pistons. The last time the Celtics advanced to the NBA Finals was in 1987 when they eliminated Detroit.

Both teams were in the second round of the playoffs for the first time since shortly after their championship years, when they often met in May. Detroit and Boston split four playoff series between 1985 and ’89, and last met in 1991 when the Pistons beat the Celtics in the second round.

“It’s a great source of pride for these players and this coaching staff to have this franchise back where it belongs,” Boston coach Jim O’Brien said just before boarding the team bus. “We’ve accomplished a lot of things we haven’t done in a long time, but there’s still a lot that could be accomplished.”

The Celtics will play the winner of the New Jersey-Charlotte series. The Nets lead 3-1 and play host to the Hornets tonight.

“I think they have a great chance to go the finals,” Detroit’s Jerry Stackhouse said. “If it’s New Jersey, which it looks like it’s going to be, I think they match up really well.”

The Pistons clearly did not have answers to many of the problems Boston presented in the series. After beating a weary team by 12 points in Game 1, the Pistons lost four straight while shooting under 40 percent in each game.

“That’s the same defense we’ve been playing all year, but you never expect to hold one of the best shooting teams down like that,” O’Brien said. “We made them struggle for a shot on every possession and that tires a team.”

While Detroit couldn’t seem to make a key shot or stop, the Celtics made many from several sources.

Kenny Anderson added 17 points, Antoine Walker, who fouled out, had 16, Rodney Rogers scored 14 and Tony Battie added 10 as the Celtics improved to 21-0 in Game 5s when leading a series 3-1.

“We grew as a team,” Walker said. “It was big tonight. We got different contributions from everybody and this is a total team victory.

“I thought at the beginning of the playoffs, we had an opportunity to do something special, but obviously we had to put it together. I think the Philly series really taught us a lot. I think right now we have an opportunity of a lifetime and we have to take full advantage of it. Being in the Eastern Conference finals is going to be huge for us.”

Detroit’s Chucky Atkins scored 22 points, Corliss Williamson scored 15 of his 17 points in the final quarter to bring the Pistons back briefly and Michael Curry added 15.

While Celtics standouts Walker and Pierce were in foul trouble, Detroit’s lone star Stackhouse had an off night, scoring eight points on 3-of-18 shooting.

“It’s a tough thing to swallow for me because scoring has been something I’ve hung my hat on,” Stackhouse said.

The Pistons joined a long list of teams unable to overcome a 3-1 deficit. Just six teams in NBA history have won playoff series after trailing 3-1.

Boston controlled much of the game, but Detroit got back it as Pierce and Walker both picked up their fifth fouls early in the final quarter.

The Pistons began the fourth quarter by outscoring Boston 10-2 with Williamson getting eight points to pull within 66-65 with 9:14 left. Anderson answered with a basket and when Detroit pulled within one twice over the next couple minutes, Anderson and Rogers scored to give the Celtics a cushion.

“They made key plays down the stretch and we couldn’t,” Curry said.

Pierce and Walker came back into the game with 4:07 left after sitting out several minutes with Boston ahead 77-72.

Pierce scored five straight points to make it 84-75 with 2:32 left.