ATLANTA -- Not even one of their better pitching performances of the year could prevent the Marlins from getting swept by the Braves in what goes down as a historically poor overall season series against their National League East rival.

Sandy Alcantara stepped up with a gem, allowing one unearned run in seven innings, but Freddie Freeman’s one-out home run off Ryne Stanek in the eighth inning evened things up and set the stage for Ronald Acuna Jr.’s walk-off single in the ninth that handed the Marlins a 3-2 loss on Thursday night at SunTrust Park.

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The way things wrapped up was all too familiar for a youthful Marlins team that now is on the brink of their 10th straight losing season. At 45-81, Miami is one loss away from last having a winning record in 2009.

Finishing the season series at 4-15, the Marlins’ .211 winning percentage is their lowest in a single season against an NL East opponent since divisional play expanded in 2001.

“They’ve been hard on us, that’s for sure,” Marlins manager Don Mattingly said. “They’re not the only team, quite honestly. Wins are getting hard to come by. There’s been a number of teams that have thumped us pretty good.”

In the ninth, Adeiny Hechavarria led off with a double, and with runners on the corners and two outs, Acuna laced the game-winner off Stanek, giving the Braves their eighth walk-off celebration.

“It's tough,” said Stanek, acquired from the Rays at the Trade Deadline. “The results are obviously not what I'm looking for, what they're looking for. But over the last three games or so, I feel like I've thrown the ball way better than my results have shown, which is definitely frustrating. One mistake here. One mistake there. Against good teams, they tend to hurt. That's kind of how it's been the past few games.”

The Marlins have now surrendered at least one home run in 23 straight games, and they are three shy of matching an MLB record. The Orioles (June 1-28, 2017), Mariners (July 6-Aug. 3, 2004) and Astros (May 14-June 12, 2001) each reached 26 games.

The Marlins are using these final weeks to further evaluate and see who fits in which roles. Stanek has been getting a chance to close, but he was unable to convert on Thursday in what would have been a two-inning situation. And he had a two-run lead slip away on Sunday in a 7-6 loss in 10 innings to the Rockies.

“We've seen good,” Mattingly said of Stanek. “We've seen bad. We're going to keep looking at this and figure out exactly where he fits.”

Conversely, as Alcantara continues to be evaluated, he’s showing front-line starter promise.

Alcantara struck out seven, and in his last three starts, the 23-year-old right-hander has a 2.08 ERA (five earned runs in 21 2/3 innings).

“I see the difference in my last three starts, I'm going deep into the games,” Alcantara said. “That's what I want. That's what my team wants. But I think that the consistency is being aggressive in the count. I'm throwing my first pitches for strikes, and finishing the hitters.”

Starlin Castro's two-run double in the seventh off Mike Soroka snapped a string of 21 straight innings without a run for the Marlins. But the lead held for one inning.

With Thursday’s defeat, the Marlins completed an 0-6 road trip that started with three losses at Colorado. Overall, they have dropped 12 straight on the road, including back-to-back six-game sweeps.

According to Elias Sports Bureau, Miami is the second team in the Modern Era (since 1900) to go 0-6 or worse on consecutive road trips -- within one season. The Orioles last did so in 2018, going 0-6 from April 13-19 and 0-6 from May 1-6.

For the season, Marlins pitchers posted a 4.39 ERA against the Braves, while Atlanta’s staff had a 2.63 ERA against Miami.

“They are a lot like other top-tier teams that we've seen,” Mattingly said. “They've been leading the division for a long time now. They let you know where you're at, and where you stand at this moment, and how much better we have to get.”