It's clearly the signature highlight so far in this Miami Heat postseason. LeBron James taking off on the fast break, reaching more than a foot above the rim, controlling a perfect lob from Mario Chalmers and delivering a powerful one-handed dunk.

Almost forgotten in that crowd-thrilling moment: That it started with defense.

Joel Anthony blocked a shot by Philadelphia's Thaddeus Young, and when Young got the ball back and tried to shoot again, Anthony erased that try as well. Dwyane Wade controlled the rebound and quickly passed to Chalmers, who in one motion sent the pinpoint feed to James for a slam that he punctuated with a long scream.

"We've been a confident bunch all year," James said.

Perhaps never more so than right now, having won 17 of 20 games since March 10 and leading the 76ers 2-0 in their Eastern Conference first-round series, which resumes in Philadelphia on Thursday night.

Miami's offense has been far from perfect. But its defense over the last seven quarters has been stifling, with Philadelphia — which raced to an early 14-point lead in Game 1 — shooting 34 percent and getting outscored by 43 points in the last 83 minutes of the series.

Since Philadelphia had that 33-19 lead in the opening moments of the second quarter of Game 1, Andre Iguodala has shot 3 of 13, Elton Brand 4 of 12, Jrue Holiday 7 of 21, and Jodie Meeks 3 of 10. Collectively, outside the paint in this series, the Sixers have made 29 of 90 attempts.

"I don't think we've been getting the good quality of shots," Iguodala said. "You've got to credit the defense. I haven't shot an open shot all series. Every time I've got the ball, I see a guy in front of me, and if you get past him there's another guy there."

If the Heat could script what they would want an opponent to say about their defense, those would likely be the exact words.

And if there was any chance Miami was looking ahead to a potential East semifinals trip against Boston or New York, Philadelphia probably put that to rest by making the Heat scurry in Game 1.

"They have our full respect," Heat coach Erik Spoelstra said. "And if the first game doesn't grab your attention, how dangerous this team is, then we wouldn't get it. We kept on mentioning in the huddles, 'No exhale.' There's no opportunity to relax against that type of speed. Speed kills in this league."

With the 2-0 lead, Miami took Tuesday off, although many players were expected to get some individual work or treatment.

Defense is the cornerstone of the philosophy and culture that Heat President Pat Riley installed when he came to Miami in the mid-1990s, and they remain the blocks on which everything is built. The Heat call it "Five guys on a string," their way to say defense should have all five players moving in rhythm and making offenses react to them instead of the other way around.

So far, it looks playoff-ready.

"It's not just about one person," Wade said. "It's about all five doing their jobs. ... It's a whole team thing and we never look at someone and say individually, 'You got hit for 30 tonight.' It's always what we need to do better as a team."

In fairness, that doesn't happen often.

Of the 550 instances in the NBA where a player scored 30 or more points during the regular season, the Heat gave up only 15 of them. By comparison, Miami players scored at least 30 on 55 occasions.

The 19,600 Heat fans who showed up for every home game this season seemed to split their loudest loyalties between Wade and James, serenading them both at times with "M-V-P" chants along the way.

But in the playoffs, Anthony — the backup center — is even getting them as well. Bear in mind, he averaged a robust 2.0 points in the regular season, and has added seven points in the two games against Philadelphia.

"He does a lot for that team that goes unnoticed," Iguodala said.

Defense has more than masked a bit of offensive woe for Miami as well.

Chris Bosh has been strong, with double-doubles in both games of the series and scoring 46 points on 57 percent shooting. James struggled with his shot in Game 1 (4-for-14), but is still averaging 25 points in the series. And Wade — slowed by headaches — hasn't even found a groove yet. He's scored a total of 31 points so far, his lowest two-game postseason stretch since his initial appearance in 2004.

Nonetheless, the Heat are halfway to the second round.

"Let's give it to them," Sixers coach Doug Collins said. "They're a terrific defensive team."