There's an obvious explanation to this, then there's the lesser-known explanation.
The obvious reason why the Heat turned around their series with the Hawks and took a 2-1 lead after getting shellacked in Game 1: Dwyane Wade. In game 1 he struggles and scored only 19 points. The Hawks shut him down after he averaged over 30 for the season. In the next two games, Wade led the Heat to big halftime leads, finishing the games with 33 and 29 points, respectively. That puts him just at his season average of over 30 ppg.
The Heat can't win without their MV3, and that's been known.
However, there is another explanation for the Heat's turnaround: Jermaine O'Neal, who has averaged just over 20 points, 8 rebounds and 3.5 blocks in the two wins after managing only 5 points and 2 rebounds in the game 1 loss.
This is why the Heat traded for him back in February, to complement Wade. Any other role player on the Heat can step up and score 15-20 points for any given game. Those players are interchangeable when it comes to scoring: you can get 15-20 from Michael Beasley, Daequan Cook, Udonis Haslem, Mario Chalmers or even Jamario Moon on any random night. However, the Heat need a low-post presence to go with Wade's game. That's what O'Neal adds to the team: another dimension, a low-post threat, something that all successful playoff teams have.
I don't know how long to expect these types of games from the againg O'Neal, who has a record of knee injuries. However, as long as he is putting up these numbers, and as long as Wade keeps doing what he has been doing all season, then the Heat will continue to beat the Hawks.
If those numbers persist into the next round, then, dare I say, the Heat might stand a chance against LeBron and the Cavs. But I won't count our chickens before they hatch.