Seven Hawks scored in double figures, led by Paul Millsap's 26 points on 8-of-13 shooting. His partner in crime in the frontcourt, Pero Antic, scored 17 points as Atlanta dominated inside all night long.
The Heat had no answer for the balanced attack of the Hawks, and their own strong offensive performance wasn't enough to overcome their lack of defense on the other end.
Key Player Grades
LeBron James, Power Forward/Small Forward
As you'd expect, LeBron was his typically dominant self on the offensive end. He went 11-of-21 from the field on the way to 30 points and six assists.
The problem was his inability to make much of an impact defensively. You can't put a ton of blame on any individual Miami defender, as their scheme is so dependent on rotation and teamwork, but LeBron's struggles weren't easy to ignore.
He spent time on both Millsap and DeMarre Carroll, both of whom went 8-of-13 from the field.
It wasn't long ago that James was one of the most feared defenders in the NBA. He often looks nowhere near as engaged mentally these days, and the Heat may be following his lead.
Miami's now 2-4 in its last six games and allowing 103.8 points a game during that stretch.
Chris Bosh, Center/Power Forward
In the absence of Dwyane Wade, Miami needed Chris Bosh to step up and be the second scorer. He did so effectively for three quarters.
Bosh finished the game with 21 points, but shot 7-of-18 from the field, including just 2-of-7 in the final frame when the Heat needed him most.
Even more damaging than Bosh's missed shots, though, was his defense around the rim. Atlanta's frontcourt trio of Millsap, Antic and Elton Brand combined for 51 points on 19-of-28 shooting.
Bosh spent most of his time on Antic and Brand and did little to deter either of them. He also failed to make an impact in Miami's defensive rotations, as Atlanta won the battle of points in the paint 48-34.
Ray Allen, Shooting Guard
Ray Allen broke out of a shooting slump in a big way, going 5-of-5 from the field and 4-of-4 from three-point range. He finished with 14 points, seven rebounds and three assists, giving Miami more than it should have needed from the shooting guard position with Wade out.
He also did a good job against Kyle Korver, helping to hold Atlanta's sharpshooter to a 3-of-10 performance.
Mario Chalmers, Point Guard
Mario Chalmers did a good job of taking Hawks starting point guard Jeff Teague out of the game (Teague went 1-of-7 from the field in 20 minutes) but somehow struggled with backup Shelvin Mack.
Obviously, Chalmers isn't entirely to blame for Mack's 13 points and seven assists (Norris Cole spent time on him as well), but he was burned a few times by the third-year pro, who's already played for three different teams.
On the other end, Chalmers was solid. He scored 17 points while shooting 50 percent from the field.
Shane Battier, Small Forward/Power Forward
Shane Battier scored 11 points on 3-of-3 shooting, but all three of those makes came in the first quarter. After that period, he did very little to positively impact the game.
He was another culprit for Miami's poor defense as well, though it's tough to fault him when he finds himself on bigger players like Millsap.
Coach Erik Spoelstra may need to rework his rotation to include more size if the defensive struggles persist.
Norris Cole, Point Guard
Cole played 29 minutes off the bench, as Chalmers found himself in foul trouble a couple of times.
As was already mentioned, he was one of the defenders tasked with slowing down Mack. In addition to his seven assists, Mack turned the ball over just once. Neither Miami point guard was able to slow him down, as he got to the lane at will.
In addition to his defensive struggles, Cole's shot was off as well. He scored just seven points on 2-of-7 shooting from the field.
On the bright side, he did have eight assists to somewhat offset his poor defense, committing four turnovers in the process.
Spoelstra seems to be among the most erratic coaches in the NBA when it comes to rotations. A few weeks ago, Michael Beasley was the team's top reserve scorer, and he can barely get off the pine now.
He played just three minutes in this one and missed his only shot attempt.
Beasley is not the only player off the Heat bench who's experienced both feast and famine when it comes to playing time. The same can be said for Rashard Lewis, Udonis Haslem and Roger Mason Jr.
Not knowing your role and having no consistency in when you're playing or not playing make it very difficult to get into a rhythm or groove.
That appeared to be the case for Miami here, as the reserves went 6-of-19 from the field for 21 points.
The Heat's struggles over the last six games could have something to do with the fact that all have been on the road.
They'll be back in Miami on Tuesday to take on the Boston Celtics at 7:30 p.m. ET.
Some home cooking against a 14-28 team could be exactly what the Heat need to get back on track.
For 140-character pearls of wisdom from Bleacher Report's Andy Bailey, follow him on Twitter: @AndrewDBailey.