WELL, I definitely had that pegged wrong.

I had the false impression that the Sixers were the team with the young, athletic and tireless legs that could play on Monday, rest on Tuesday and then come back running like gazelles again on Wednesday.

On the other hand, the Boston Celtics, I figured, had old, decaying legs and would risk getting charley horses if they didn't get a long, hot soak before going at it again.

The compressed schedule of the second round of the playoffs, with a game every other night, was supposed to work against the Celtics and in favor of the Sixers.

Not on Wednesday.

The Celtics didn't just lay down a 107-91 beat down on the Sixers; they did it by running them out of the Wells Fargo Center.

The homecourt advantage the Sixers stole by winning Game 2 didn't last long as the Celts bum-rushed South Philly to take a 2-1 series lead.

This was a sprint, the type of race in which the Sixers should have had the advantage, but it was Boston that ran at full speed from start to finish.

The Celtics overwhelmed the Sixers with their activity on both ends of the court.

Old legs got young.

Kevin Garnett may turn 36 years old on Saturday, but he looked like he had turned back the clock 10 years by punishing the Sixers for a game-high 27 points and 13 rebounds.

"When we lost the other night, all we heard was [the Sixers],'' said Garnett, who again treated Sixers center Spencer Hawes as if he wasn't even on the court. "We were going to come out with the same energy and effort. We're here to win. It's all good."

Perhaps no Celtic played with a bigger chip on his shoulder than Paul Pierce.

He hasn't used it as an excuse, but Pierce has clearly been affected by the MCL sprain in his left knee. He's the type of player who feels that if he steps on the court, he should play at the same high level he always does.

That didn't happen in the first two games, and Pierce has been annoyed by the credit Sixers swingman Andre Iguodala had gotten for limiting him to a combined 21 points. And when Pierce started Game 3 by missing his first six shots, it looked like Iguodala's defense was going to again make for a frustrating night for him.

Honestly, when Pierce clanked a layup off the bottom of the rim with about 5 minutes remaining in the first quarter, he didn't look like he had the explosive lift that makes him so dangerous when driving to the basket.

But with about 1 1/2 minutes left in the quarter, Pierce got a pass from Rajon Rondo in the lane and threw down a vicious dunk. Less than 30 seconds later, a scowling Pierce was dunking again.

Pierce played angry the rest of the game and finished with 24 points and 12 rebounds.

"That's who he is," Celtics coach Doc Rivers said. "Paul is just a grinder. You look at him at times and wonder how this guy is getting open. He just has great fundamentals. He never does it with speed. He just knows how to play basketball.

"You could see early on he missed two layups, had no lift. Then all of a sudden he dunks the ball down the lane. He gets five offensive rebounds. I think guys like Pierce and Kobe [Bryant], they just have something in their minds that make them who they are."

But it wasn't just the veterans, Garnett and Pierce, who stepped up for the Celtics.

The youngest of the "Big Four" - point guard Rajon Rondo - again torched the Sixers with his complete control of the pace of the game. In Game 3, he had 23 points and 14 assists, bringing his totals for the series to 60 points and 44 assists.

Rondo is doing whatever he wants whenever he wants, and the Sixers don't seem to be able to do anything about it.

"It's just take what the defense gives me," Rondo said. "It just developed that way. They came out running at us, but we got out into team transition when we got a couple of stops early. It's defense first."

Rivers said people have a misconception that the Celtics don't want to run against the younger legs of the Sixers.

"We want to run," Rivers said. "We just don't want [the Sixers] to run. We got a lot of stops that allowed us to get easy baskets.

"Both teams play tough defense, so you have to get some easy baskets in a series like this."

The Sixers' marketing phrase this season has been "Passionate. Intense. Proud."

The same things easily apply to the Celtics. This is a group on a ride-into-the-sunset mission to win one last title. They have to know that with Chris Bosh out indefinitely with an abdominal strain, the Miami Heat isn't nearly as formidable - not that the Celtics were afraid of them anyway.

Boston has little desire to get into a drawn-out slugfest with the Sixers.

"I really believed we needed this game and we were really focused," Rondo said. "We played two close games at home, and we want to send a message to [the Sixers].

"I thought we did a good job of that."

Perhaps the worst thing for the Sixers was that the Celtics had such control of the game that no one but Rondo played 40 minutes.

In minutes, Garnett barely played a little more than half the game, and Pierce played three quarters.

With a quick turnaround to Game 4 on Friday, every extra bit of rest helps - even if the Celtics didn't look like they needed it.

"This was a team that you could see did not want to be down 2-1 going into Game 4," Sixers coach Doug Collins lamented. "This was a much different team than we saw in Boston."