Now, Atlanta is once again reeling after being unable to make up ground on the two teams -- New York and Philadelphia -- it is chasing in the National League East, and the four clubs the Braves are behind in the NL Wild Card standings.
"If we win the last four in a row heading into New York, we're feeling good about things," said Atlanta third baseman Chipper Jones, who got the Braves on the scoreboard with a two-run homer in the first inning Sunday.
Cormier appeared headed for his third straight win, settling down after an RBI single by D'Angelo Jimenez in the third inning to retire eight in a row at one point.
That streak ended with a Dmitri Young single, which Cormier let snowball by allowing a double to Austin Kearns and Church's home run. Cormier dominated Church in the Washington center fielder's first two at-bats, striking out Church both times on seven combined pitches.
In those at-bats, Church showed a weakness for curveballs out of the zone, and Cormier tried to attack Church with the same in the sixth. But Church laid off one and worked a seven-pitch at-bat before smacking a hanging breaking pitch over the 400-foot marker in center field.
"You get that far and you're one pitch away, basically, from keeping the lead and everything," Cormier said. "If I make the pitch I needed, we still have the lead and we probably get the win. It's very disappointing in that we weren't trying to give in [to Church], and that's what happens."
Church's homer ultimately saddled Cormier with his fifth loss of the season, but it by no means ended Atlanta's chances to get him off the hook and win.
Jason Bergmann pitched six innings, allowing four hits and three runs with six strikeouts -- numbers that proved good enough for Bergmann to pick up his third career win against the Braves, half of his career total.
Washington's bullpen was given the responsibility to hold the 4-3 lead and it did so, but not without enduring some potentially perilous situations.
Luis Ayala worked himself into a bases-loaded jam in the seventh before being relieved by Arnie Munoz, a left-hander who had the task of retiring Chipper Jones with two outs and the game on the line.
Jones had never faced Munoz, a September callup who was making just his 14th lifetime appearance, and Jones grounded meekly into a fielder's choice to end the inning.
"When you don't know what a [pitcher's] got, what his tendencies are, what type of stuff that he has, it's advantage pitcher," Jones said. "I got myself out trying to make something happen.
"If I were familiar with the guy, I would have formulated a game plan before the at-bat and tried to stick with it. But that all goes out the window in September when you've got guys that you've never faced before."
Mark Teixeira led off the bottom of the eighth with his 11th homer since joining the Braves on July 31 and 24th overall this season to make it 6-4.
A Brian McCann single put the tying run on base with one out, but Nationals reliever Jon Rauch induced a first-pitch double-play groundout to end Atlanta's last threat of the day.
"We had some runners on, and we had the right guy up there [in the seventh inning] with Chipper," Braves manager Bobby Cox said. "He's been on fire, you just can't do it every single time. He drove in the first two runs with a homer, but you can't do it every time. It would have been nice, we just couldn't pull it out."
The Braves have once again gone into desperation mode, a mentality they seemed to have had perfected after winning four of five games following a sweep by the Mets to start the homestand.
They'll look to exact revenge on the Mets starting Monday at Shea Stadium, but a sweep wouldn't knock New York from its perch in the NL East and would succeed only in giving the Braves hope -- which hasn't necessarily translated into success yet this season.
"You hate to say you've got to win out," Jones said. "But you find yourself at certain points of a game like today wondering how you lost. You look back over the course of the season, and we've said that a lot this year."