BIRMINGHAM, Mich. — It didn’t take long for Flip Saunders and the rest of the Detroit Pistons to realize Kevin Garnett and the Boston Celtics came ready to play in Game Three of the Eastern Conference finals Saturday night.

On the game’s first possession, Garnett caught the ball in the post, felt a defensive double-team heading his way and slipped a pass to Paul Pierce for a dunk. The next time down, Garnett caught the ball inside again. He took one dribble and quickly found a cutting Kendrick Perkins for another jam. The Celtics passed to Garnett the third time they had the ball, too. This time he faced his defender, Antonio McDyess, and drilled a 15-foot jump shot in his face.

Boston’s 6-0 lead grew to 11-0 and the Pistons never really recovered. The Celtics enjoyed a wire-to-wire, 94-80 victory, easily their most important win of the playoffs. Boston leads the series, 2-1, and will be out to drive a thick nail into the Pistons’ playoff coffin in Game Four tonight.

“Especially at the beginning of the game, I thought Boston, a lot because of the way Garnett was, exerted their will at the beginning of the game,” said Saunders. “They just came out extremely aggressive. The first play of the game we gave (Garnett) a back-door cut, wide-open lane. That’s usually not the way you want to start. It just kind of snowballed and started from there.”

While the Pistons’ inconsistent starts have dogged them throughout these playoffs, that’s something the Celtics rarely worry about. They have Garnett, after all, and his ultra-intense, competitive nature rubs off on everyone. Celtics fans see the way Garnett prepares to take the floor, talking to himself, high-fiving teammates and focusing through the din of music blaring before tipoff.

But that’s only the public’s view of Garnett’s intensity. His coaches and teammates see even more. There’s very little pregame chit-chat, if any. He likes to be left alone with his thoughts.

“We laugh about it in the locker room,” says Doc Rivers. “We (ask) all the time ‘Are you breathing?’ Breathing helps.”

Is Garnett ever too intense?

“He’s always too intense. There’s no other line. It’s intense and too intense. But that’s who he is and what makes him great,” said Rivers.

Throughout the playoffs, Garnett’s efforts can be termed consistently great. Big Three sidekicks Pierce and Ray Allen (not to mention opposing stars LeBron James and Chauncey Billups) have all struggled at times in the postseason, but not Garnett. He’s been the Celtics’ stabilizing force, averaging 20.9 points and 10.1 rebounds in 17 playoff games. He’s scored 20 or more points and grabbed 10 or more rebounds in 10 games. In the Detroit series, he’s pushed his numbers up to 24 points and 11 boards a game.

“Just being aggressive, nothing more, nothing less than that,” Garnett said yesterday, matter-of-factly. “Every time I have a one-on-one, (I) try to take it. Other than that, trying to make plays for my teammates.”

His teammates are happy to have him on their side. Allen compared Garnett’s consistent, superb play to that of other centers who’ve taken their teams deep into the playoffs.

“It’s similar to all the teams that have won championships in this decade, like Tim Duncan with the Spurs. You have to have that guy that’s going to be your rock,” Allen said.

Garnett gives the Celtics a big edge in every series. On offense, he can score inside or out and baffle multiple defenders. McDyess, Rasheed Wallace and Jason Maxiell have all guarded Garnett at times for Detroit.

“We focus on going to Kevin. He is the guy we try to establish from the jump,” said Pierce. “He’s definitely getting his opportunities and he’s making the most of them. He’s one of the most unguardable guys you have at that height at his position. We try to feature him every night.”

How good is Garnett defensively?

“Defensive player of the year. That’s what you expect,” Pierce said. “Both ends of the court he’s playing phenomenal basketball.”

Rivers says he purposely limited Garnett to 32.7 minutes a game in the regular season with an eye on more action in the playoffs. He’s seeing 38 minutes a night now but plays so hard that Rivers has no choice but to substitute for him.

“He taxes himself every game. There’s times when you just literally have to get him out of the game,” Rivers says.

Garnett has never played in the NBA Finals. Now just two wins away, that is clearly his goal, but he’s not about to bite on that question. More combat with the Detroit Pistons awaits.

“It’s not a get-one-and-be-happy type of series,” Garnett said after Game Three. “You have to take it one game at a time, fix what we didn’t do right and be better in the next game. We just won a game, nothing more, nothing less.”Tonight

Celtics vs. Pistons

8:30 p.m.

kmcnamar@projo.com