It was Atlanta's first shutout and complete game since last July 1, when Jair Jurrjens shut out the Orioles. Beachy, who gave up only five hits, four of them singles, allowed only one runner to reach third base and retired 13 of the last 14 hitters he faced.
"He pitched great. He spotted up everything tonight," said catcher Brian McCann. "Every changeup he threw was down, every fastball was located. He was smart. He put them away with his pitches.
"He knew last year getting into the fifth, the sixth inning wasn't good enough. I think that was his No. 1 goal going into this offseason was to get deep into ballgames, and I think this game right here just showed when he puts a plan together and puts it in action, how good he really is."
"He had that look in his eye tonight," added third baseman Chipper Jones, who was one of four Braves with two hits. "He was focused, he knew we needed to win this game very badly and he was going to come out and give us the best effort possible. He didn't walk guys, he didn't fall behind guys, he kept their speed off base, kept them from getting their running game started. By far his best start since he's been here."
The Braves had double-figure hits for the third straight game on the homestand, during which they hit .307 (42-for-137).
"That's what our lineup is -- tough outs, one through nine," said first baseman Freddie Freeman, who hit his seventh homer of the season in the third inning to begin a two-out, two-run rally that gave Atlanta a 3-0 lead. The homer was his first since sitting out on Tuesday night with eye issues.
Jones, Michael Bourn, Martin Prado and Tyler Pastornicky all had multi-hit games for the Braves, who scored in four of the first five innings to race out to a 7-0 lead.
Beachy (5-1) did the rest. He brought a 1.60 ERA into the game and lowered it to 1.33, striking out six, while not walking a batter. He has now allowed two or fewer earned runs in four straight starts and in nine of his 10 appearances this season. He even added an RBI single in a three-run fifth, an opposite-field single that scored Jones and was his fourth RBI of the season, easily tops among Braves pitchers.
Ricky Nolasco (4-2) took the loss for Miami, his second straight defeat and second consecutive start in which he was unable to make it out of the fifth inning. Nolasco had pitched at least five innings in each of first six starts. He allowed four runs (all earned) on seven hits, walked one, striking out two and hitting a batter in four innings.
Bourn, who didn't start for the first time in 2012 on Wednesday night, lined Nolasco's second pitch into left-center for a single, then came around to score as Prado's drive to right-center glanced off the glove of a diving Emilio Bonifacio.
The Marlins center fielder made a valiant effort, but the 5-foot-11, 204-pound Bonifacio appeared to take his eye off the ball to make sure he avoided hard-charging right fielder Giancarlo Stanton, who stands 6-foot-5, 246 pounds.
Beachy said getting that first run and, more importantly, protecting it was crucial.
"It's big for me after we [score first] to go out and put up a zero to try to carry that over and bring us back in," he said. "I was able to do that. Having that lead really relieves a lot of stress."
In the third, Nolasco retired table-setters Bourn and Prado, but then saw the Braves use some two-out thunder to extend the lead to 3-0. Freeman took a 1-0, letter-high fastball out to right for his seventh homer of the season. Dan Uggla followed by coming back from a 1-2 count to draw a walk, and he scored when Brian McCann went the other way, dumping a fly ball down the left-field line that just eluded the diving Logan Morrison.
The Braves added a run in the fourth on a Bourn single and three in the fifth off reliever Chad Gaudin on RBI hits by Jones, Heyward and Beachy.
The only question after the fifth was how far Beachy could go.
Braves manager Fredi Gonzalez had no doubt he was going to let his starter go for the complete game.
"No doubt at all," said Gonzalez. "The only question would have been how far we could push him. That was the most pitches he's thrown in his career."