Jason Heyward homered, Dan Uggla added a two-run double and Juan Francisco broke open the game with a pinch-hit two-run single.
The last time Buehrle did not go five innings was on Sept. 4, 2011, when he was with the White Sox. He lasted 3 1/3 innings that day.
"Buehrle has to throw strikes," manager Ozzie Guillen said. "When Buehrle is off, walking people and [getting into] heavy counts, you will run into trouble. They're going to put the ball in play against him."
The Braves drew 102 pitches out of Buehrle, who walked four for the second straight start. He hadn't gone back-to-back starts with that many walks since June 4 and June 10, 2006. In addition, in each of his last three starts, he hasn't gone deeper than five innings.
"Three consecutive for me, going out in five innings, it's really not acceptable," Buehrle said. "I'm just falling behind too much and having to make pitches in tough spots. I'm in hitters' counts a lot. It's just one of those little stretches I'm in right now."
The Marlins had their chances off Atlanta starter Tommy Hanson, who gave up one run over five innings in collecting the win.
Miami went 3-for-9 with runners in scoring position and left 10 on base.
The lack of offense prompted Guillen to remind his players that they are being evaluated.
"That's been our script. We see the same thing, day in, day out -- a lot of strikeouts with men on base," he said. "A lot of bad at-bats with men on base. A lot. Too many. When you do that, and opportunity comes once, and you don't take advantage, they will take advantage.
"This is a heads up for some people out there. They better start putting it together, because the door is going to be open pretty quick. When I see games like that, day in, day out, I start to think, 'How are those guys still in the big leagues?' Well, what should we do? Maybe they feel a little bit too comfortable being here? Who knows?"
The way things have transgressed for Miami was evident in the fifth inning. The Marlins scored on Jose Reyes' double, which trimmed Atlanta's lead to one run. Carlos Lee followed with a hard single to left. Reyes raced home with what could have been the tying run, but he was tossed out on a perfect strike from left fielder Martin Prado.
"[Prado] never quit on the play and made a throw right on the money," Atlanta third baseman Chipper Jones said. "That was a momentum shifter. [Reyes scoring] ties the game and who knows? It might get Tommy out of the game at that point. But it kept us on top, and we were able to chip away and finally put it away."
Prado's defensive gem inspired Atlanta's four-run fifth inning, which broke open the game. Uggla's two-run double ended Buehrle's night.
Carlos Zambrano, replaced in the rotation by Wade LeBlanc, made his first relief appearance since Aug. 4, 2010, and surrendered the two-out, two-run single to Francisco.
Reyes' double extended his hitting streak to 17 games. It's the longest active streak in the Majors and is three games shy of his career high, set from July 17 to Aug. 7, 2005. He also has a string of six games with an extra-base hit, his career best.
Although Reyes gave the Marlins a scoring chance in the third inning, the team couldn't capitalize.
The Braves scored first, in the bottom of the third, grabbing the lead on Heyward's two-out homer to right field.
Heyward has 17 home runs on the season, with four coming off Miami pitching in nine games.
The Braves' right fielder also has eight RBIs while facing the Marlins. His homer and RBI totals are his high against any opponent.
"The reason they are where they are is because they're playing well," Guillen said. "Their defense is good. Their offense has been on fire. Today we should have taken advantage of their pitcher early in the game, and we didn't. When you do that against them, you're going to run into trouble, because their bullpen is pretty good. ... I'm not going to say it's going to be impossible, but it's going to be tougher than [facing] the guys who started the game."