Doumit went 3-for-5 Sunday with two RBIs and a run scored. His real heroics came with two outs in the bottom of the 10th.
Doumit ripped a two-out fastball off Braves pitcher Takashi Saito to give the Pirates the win. Doumit said he was just trying to hit the ball hard to get on base and didn't know how to feel after he saw the ball clear the fence in right field.
After the game, he put his first walk-off homer into perspective.
"It was thrilling," he said. "Every hitter dreams of doing this. This one feels pretty good."
Doumit said the walk-off was that much more enjoyable because it gave the team a win in a game where starter Zach Duke deserved to earn a victory.
Duke pitched a seven-inning gem without yielding an earned run, giving up seven hits while striking out five and walking none. He had to settle for a no-decision, however, after reliever Evan Meek gave up a home run in the eighth inning to Eric Hinkse -- his second solo shot in as many games.
"Once again we showed we're not just going to roll over," Doumit said. "We got a really great performance from Duke. We fed off of him."
Doumit felt all of Duke's pitches were working well Sunday, and thought his command was superb. The lefty thrived on keeping his pitches down and attributed that to his stellar performance.
"My command was good and I kept the ball low," he said. "I know my strength, and my strength is getting ground balls."
The Pirates' big concern coming into this game was leaving runners on base, as the team had stranded 22 runners in the previous two games against the Braves. They again had problems knocking in runners on base Sunday, stranding 11 more.
While Russell acknowledged the team's continued struggle with leaving men on base, he was just happy to end the series with a win.
"We struggled again with scoring runs, but the guys never laid down," Russell said. "We played pretty well against Atlanta this series, we just couldn't collect on all the hits. Today, Ryan got that big hit for us. He had a good game for us and I'm glad he capped it off."
Closer Octavio Dotel got his second win of the season after pitching a scoreless 10th inning.
The Pirates' only runs before Doumit's home run came in the sixth inning, when they chased Braves starter Kris Medlen after scoring two runs.
Andrew McCutchen tripled into the gap in right-center field to start the rally. After a Garrett Jones walk to put runners at the corners with one out, Steve Pearce hit a sacrifice fly to right field that scored McCutchen.
Lastings Milledge reached base on an in-field hit, then Doumit singled to right to put the Bucs ahead, 2-1.
Pearce is now batting 5-for-10 with four RBI's and two runs scored in the past three games he's started.
Duke's ability to limit the Braves to one unearned run came mainly because he quickly erased any batters he allowed to reach base.
Duke got Martin Prado, the Braves' leader in batting average, hits and runs, to ground into double plays to end the first and third innings. He also got Brent Clevlen to ground in to a double play to end the fifth inning after issuing a leadoff hit to David Ross.
Duke also got out of another jam by retiring three consecutive batters after issuing a leadoff double to Omar Infante in the sixth inning.
The only run scored on Duke was unearned following an error by shortstop Ronny Cedeno in the second inning.
Cedeno did, however, add to his streak of reaching base safely in 14 consecutive games after singling in the eighth, although he also left five runners stranded on base throughout the day
Another Pirate finally broke a less admirable streak, as leadoff man Aki Iwamura snapped an 0-for-34 slump with a single in the bottom of the fifth. He also doubled in the seventh.