It was Cordero's fourth blown save of the season. He was not available for comment after the game.
"We had enough runs on the board to win tonight. All we had to do was get three outs, and we didn't do it tonight. You have to win some of those games like that," said manager Frank Robinson.
It would get worse for the Nationals in the 10th inning. Mike Stanton started the frame by giving up a leadoff single to Brian McCann, then it looked as if the Nationals would get out of the inning. After Julio Franco sacrificed McCann to second and Rafael Furcal was walked intentionally to put runners on first and second, Stanton was able to get Kelly Johnson to pop up for the second out.
Robinson then took Stanton out of the game in favor of Luis Ayala, who had a tough time finding the plate.
On a 1-1 pitch, Ayala hit Marcus Giles to load the bases. Andruw Jones was the next hitter, and he walked on four straight pitches to force home pinch-runner Jeff Francoeur.
The losing pitcher was Stanton, while Chris Reitsma took the victory.
"It's a tough one because of the situation. Chad has pitched so incredibly well this year," said Stanton. "They put it in our hands, and we were not able to get the job done."
After the final pitch of the game, Ayala and catcher Brian Schneider argued with home plate umpire Bruce Dreckman for a couple of seconds, saying that ball four was actually a strike. But the replay showed that Dreckman made the right call, as the ball was on the outside part of the plate.
Robinson even questioned what Ayala was trying to do on the 3-0 pitch.
"It wasn't a very good outing for Ayala," he said. "He hit a batter, and when you go 3-0, you don't have much of a chance, and then you throw a marginal pitch on 3-0. That's not very good.
"You throw the ball at the middle of the plate. Do you think Jones is swinging on 3-0? No. If he is, let him swing the bat. [Ayala] tried to make a perfect pitch -- outside corner."
The Nationals have lost seven of their last 10 games since the All-Star break. After spending 51 consecutive days in first place, they now find themselves a game behind the Braves in the National League East, though they lead the Wild Card race by two games over the Astros.
Stanton, a veteran of postseason play, said that it's too early for the Nationals to think that they must beat the Braves in this three-game series.
"Obviously, you would like to win them, especially against the teams you are battling with, but it's still the end of July with 60 some-odd games to go," he said.
It looked as though Livan Hernandez's 10-game losing streak against the Braves was going to come to an end. The last time he defeated the Braves during the regular season was on Aug. 18, 2000, when he was a member of the Giants.
Hernandez pitched eight innings and allowed one run on five hits. He struck out five batters and walked only one.
Robinson was questioned as to why Hernandez didn't pitch the ninth inning. Robinson's explanation was that it was hot on the field and that Hernandez was still experiencing problems with his right knee.
"Livan gave us a tremendous eight innings, but we couldn't close the deal. We couldn't ask him to do any more," said Robinson.
Hernandez's counterpart, John Smoltz, was just as effective. He pitched eight innings and gave up two runs on four hits. He struck out four and walked two.
The Nationals took a 1-0 lead against Smoltz in the third inning, when Brad Wilkerson drove in Brian Schneider with a single to right.
Two innings later, Jose Guillen singled up the middle to drive in Hernandez to give the Nationals a 2-0 lead.
The Braves cut the lead in half in the bottom of the seventh inning, when LaRoche took Hernandez's first pitch and homered over the right-field wall.
"I threw a slider inside. He was cheating and got right there in the zone," said Hernandez.