Their old legs may still cost the Boston Celtics this series against the younger, fresher Sixers. For a night, though, old heads prevailed over young legs in a big way.

"This was a team that you could see did not want to be down two (games) to one, playing Game 4," Sixers coach Doug Collins said. "You could just see. They've been in a lot of these kinds of games. They know how important a swing game is to get that home court back. And they played great."

The Celtics may have knee problems and foot problems and ankle problems. They may be sore and achy and stiff-legged. But they are still a team with a championship pedigree, a team with legitimate superstars. They were not about to panic after two close games in Boston. If anything, they looked annoyed as they swatted the Sixers, 107-91, Wednesday night.

It was just one basket among many. But everything about this game was in a dunk by Paul Pierce in the first quarter. The Celtics' mainstay had missed a couple of layups. His sore knee had left him looking slow and old through the first two games. Now he came driving down the lane, fire in his eyes, and slammed the ball angrily.

"That's who he is," Celtics coach Doc Rivers said.

From that dunk on, the Celtics outscored the Sixers by 20.

There is no way to know from Game 3 whether the Celtics have awakened, realized the Sixers could actually win this series and snatched control, or whether Boston emptied its fuel tanks Wednesday night. Game 4 will be the acid test. If the Celtics can rebound with another effort like that in 48 hours, the Sixers are in trouble. Big trouble.

Collins has seen everything in basketball four times – as a college player, a pro player, a coach and a broadcaster. His sense of the Celtics is probably accurate. This is a veteran team that has been bypassed in the Eastern Conference by Miami and Chicago.

Now, thanks to the Sixers, Chicago is gone. Miami has lost Chris Bosh to injury and lost Game 1 of its second-round series to Indiana. The landscape is changing.

"You can tell with them," Collins said. "I think they're looking at that other series a little bit. They see Chris Bosh being out. It think they see a tremendous opportunity for themselves. I think you saw with their game tonight. This was a much different team than we saw in Boston."

It was the Boston team we've all seen plenty of times. Pierce and Kevin Garnett were themselves, and Rajon Rondo was in complete control of the game. He found his stars when they were open and scored 23 points of his own.

"Rondo was extremely serious in shootaround," Rivers said. "He set the tone for us."

Before the game, Collins worried aloud about the effect of the home crowd on his team. The Sixers seemed immune to the hostile environment in Boston, but how would they handle the pressure of playing in front of their own sometimes impatient fans.

"I'm worried about us at home, playing through some bad stretches," Collins said. "I don't want our guys to get tight. We had two bad stretches in Boston. On the road, I don't think our guys feel the pressure of the crowd. At home, against Chicago, we got down 9-3 and we missed a shot and there was a little bit of letting us know that wasn't good enough."

The change in venue turned out to be the least of the Sixers' problems. They got out to a quick start and the arena pulsed with positive energy. The crowd rewarded every basket with a jet-engine roar.

Even after the Celtics had taken control and opened a wide lead, the crowd stayed upbeat. Thad Young's slam late in the third quarter drew a huge thunderclap of applause. It made the score 87-66, meaning either these fans were terrible at math or they'd decided to reward this young team with a little unconditional love.

And why not? These Sixers have already exceeded expectations. They are playing in mid-May. They have not been intimidated by either their opponents or the spotlight so far.

After cruising past injury-depleted Chicago and splitting two one-point games in Boston, the Sixers took their first real beating of the postseason. Experienced teams know this happens and move on quickly. It is a new experience, another test for these Sixers. If they're more than just lucky, they won't let it derail them.

Game 4 will tell whether the Sixers' young heads can recover mentally faster and more completely than the Celtics' old legs can recover physically.

"I told our guys the NBA playoffs are about the ebb and flow of emotion," Collins said. "Boston has been through that. Right now, this is all new for us."