Former Atlanta reliever Mike Dunn was on the mound for the save chance. But the lefty gave up a leadoff double to Chipper Jones just before Freeman provided the heroics with a no-doubt, two-run blast to center field.
"We've lost a lot of games, and to lose that game like that is kind of heartbreaking, especially with the way the team played today," Dunn said.
Because Steve Cishek has had his struggles against left-handed hitters, Miami manager Ozzie Guillen went with the left-handed Dunn to face switch-hitting Jones, and then Freeman.
"I think the hardest thing for any manager on any team is when your closer is inconsistent, and you can't get the job done," Guillen said.
The blown save was the 21st by the Marlins. The struggles started in the first half with Heath Bell. Cishek has been used for much of the second half, but on Sept. 18, the Braves scored three runs in the ninth off him.
So Dunn was called upon.
"They're playing good this year," Dunn said of his former team. "We'll see what they can do as they move along. But I have to worry about our team. We have to be ready to play tomorrow."
Freeman was mobbed at home plate after belting his 22nd homer of the season.
"When I hit it, I knew I hit it good," Freeman said. "You don't want to celebrate too early. I hit it, and I saw him going back. Before I hit first base, I knew it was going out. That's the coolest thing that has ever happened to me."
Before the walk-off celebration, the Marlins were close to foiling Atlanta's night.
Solano belted two home runs off Kris Medlen to power the Marlins to a 3-2 lead.
Although Medlen didn't get the win, the Braves won for the 22nd straight time the right-hander has started.
Solano is the third Marlins player to record a multihomer effort in the same game he hit his first shot. Hanley Ramirez was the last to do it, on April 18, 2006.
For the second straight start, Nathan Eovaldi faced the Braves. Once again, the right-hander was effective. In six innings, he set a career high with eight strikeouts. And he yielded just two runs.
"I felt like I located the ball well," Eovaldi said. "The changeup felt real good tonight. I was able to use all four of my pitches. I kept throwing my curveball. I didn't throw too many for strikes. I just kept throwing it. I was able to get the ball inside away."
On Sept. 18 at Marlins Park, Eovaldi threw eight shutout innings against the Braves in a no-decision.
"Eovaldi pitched his butt off today," Dunn said. "Solano was extremely good at the plate. We fought and never gave up. Going into the ninth, and to just give it up on two hitters, it just [stinks]."
Solano's first home run came on his 252nd MLB at-bat. But it was his second blast that gave the Marlins the edge.
The rookie delivered a two-out, two-run shot to right-center. Greg Dobbs kept the inning alive with a floater into left field that was just out of Jones' reach.
Medlen gave up three runs and struck out eight in seven innings.
The Braves claimed a 2-1 lead in the sixth inning on Jones' sacrifice fly to right. Eovaldi struck out Martin Prado to open the inning, but Jason Heyward followed with a triple to center.
Jones did what he made a career on, finding a way to get the run home. The veteran lifted a fly ball to deep right field, enabling Heyward to cruise in with the go-ahead run.
In his remarkable career, Jones has done damage to plenty of teams. But the club he has his most RBIs against (151) is the Marlins. And in Marlins history, no player has knocked in more runs against them than Jones.
Solano extended his hitting streak to five games with a memorable knock with one out in the second inning for his first MLB homer.
The solo shot off Medlen sailed over the wall in left field. Solano also was able to receive the ball. Being on the road, the fans threw the ball back onto the field, and it was flipped into the visitors' dugout.
Atlanta pulled even in the second inning on Dan Uggla's RBI single to left. Eovaldi had worked into trouble by issuing a leadoff walk to Jones and a single to Freeman.
Uggla continues to hurt the Marlins, his former team. He now has 15 RBIs on the year against the Marlins, his most vs. any team. The next high is eight against the Phillies.
In the playoffs, Guillen feels the Braves have a chance to go far.
"I think they've got a good ballclub," Guillen said. "I'm very happy for them. Fredi Gonzalez is a good friend of mine. I have a great friend, their hitting coach [Greg Walker]. I've known Chipper for a long time. They've got a good ballclub. They've got a good, talented ballclub.
"I think with the pitching staff they have, the bullpen that they have, they have a shot."