Beachy (5-1) blanked the Marlins on five hits in his first complete game and the Braves pounded out 12 hits in a 7-0 victory that pushed Atlanta back ahead of Washington atop the National League East.
"He pitched a great game," Nolasco said. "He's going really well and he continued that."
Nolasco, meanwhile, remained tied with Dontrelle Willis for the Marlins' career record with 68 wins, as he lost his second straight outing after winning his first four decisions. The right-hander's ERA has jumped from 2.72 to 4.10.
"Ricky wasn't that bad," manager Ozzie Guillen said. "If we make a couple of plays, it's different. He threw better than it showed."
But Nolasco was certainly no match for Beachy, who had never pitched more than 7 1/3 innings in a game. He lowered his miniscule ERA to 1.33 ERA, striking out six and walking none.
Nolasco, who was taken out for a pinch-hitter after just 79 pitches, allowed seven hits and four runs in four innings. He struck out two, walked one and hit a batter.
"It was a tough call for us," Guillen said of the decision to put in pinch-hitter Austin Kearns in the fifth inning with a runner on and the Marlins down, 4-0.
"He's the manager," Nolasco said. "He makes the decision. It almost paid off."
But the Marlins couldn't score even after Kearns delivered a hit, and Beachy retired 13 of the last 14 batters he faced. The only hit was a leadoff double by Giancarlo Stanton in the seventh inning.
"He was good, but we've got to do a better job," Logan Morrison said.
The Marlins have had some big comebacks this season, but they didn't come close to mounting one this time. It just wasn't their night, as they fell back into fourth place in the NL East.
Michael Bourn lined Nolasco's second pitch into left field for a single, and Martin Prado quickly scored him with a triple that tipped off Emilio Bonifacio's glove in deep right-center field.
"Nolasco is a good pitcher. I always feel like I've got a good match against him, because he mixes pitches very well," Prado said. "But I got a good pitch to hit and I didn't try to do too much, just go the other way, and fortunately for me, it found a hole."
Nolasco kept the first-inning damage to the one run, but plenty more were to come for the Braves.
Freddie Freeman smashed his seventh homer of the season into the right-field seats with two out in the third inning, and soon the Braves' lead was 3-0. Dan Uggla drew a walk and Brian McCann sliced a double that just eluded a diving Morrison near the left-field line.
Jason Heyward was thrown out trying to steal after leading off the Braves' fourth with a single, but the Braves padded their lead to four runs anyway. Tyler Pastornicky singled, was sacrificed to second by Beachy and scored on Bourn's bouncer up the middle.
"Didn't get a break," Nolasco said. "I threw some good pitches. Even the home run was a good pitch in. Thought I threw the ball pretty well. Felt good. Just the result wasn't what I or the team wanted."
The Marlins, who had just two baserunners in the first four innings, finally mounted a threat against Beachy in the fifth. Gaby Sanchez led off with a single and made it to third when Kearns lined a hit over a leaping Pastornicky at shortstop. Kearns took second base on the throw, but both he and Sanchez were stranded when Jose Reyes lined out to right field.
"Other than that one, he really didn't have any stressful innings," Braves manager Fredi Gonzalez said of Beachy.
It was the second short outing for Nolasco, who lasted 4 2/3 innings on Saturday in a 9-3 loss to the Mets. He gave up six runs and nine hits as he battled control issues. The 29-year-old California native walked three of the first five batters he faced and later hit two Mets in a row.
Nolasco set a Marlins record with a 16-strikeout game at Turner Field in 2009, but he has had mixed results against the Braves at best. He was 5-7 with a 4.80 ERA in his previous 20 starts vs. Atlanta.
Gaudin, who had a 0.71 ERA for his first seven appearances this year, walked the first two batters he faced in the fifth, and then allowed RBI hits by Chipper Jones, Heyward and Beachy, who singled with two out.
Beachy came out for the ninth inning despite already having thrown 110 pitches. He struck out Donnie Murphy -- who had given Hanley Ramirez a breather late in the game -- and Morrison, before getting Stanton to bounce out to end the game.
Of his 122 pitches, Beachy threw 80 for strikes. The 25-year-old right-hander from Indiana repeatedly got ahead of Marlins hitters with fastballs high in the strike zone, and then put them away with off-speed stuff.
"He just pitched great," catcher Brian McCann said. "Man, he spotted up everything tonight. Every changeup he threw was down, every fastball was located."