"We threw eight shutout innings. We outhit them. We doubled them in hits. Our bullpen was great," Cox said.
Trouble is, the Washington Nationals won, not the Braves.
Justin Maxwell's grand slam off rookie Mike Minor in the second inning powered the last-place Nationals over Atlanta 4-2 Wednesday and sent the Braves to only their second home series loss this season.
Atlanta outhit the Nationals 10-5 but stranded seven runners.
"They had one major opportunity they took advantage of," said Atlanta's Matt Diaz, who had three hits.
"We had quite a few opportunities, and we didn't take advantage of many of them at all. It's really frustrating when we're not able to do that."
John Lannan (8-7) gave up two runs and eight hits in six innings for the Nationals, who have won eight of 15 meetings with the Braves this season. Joel Peralta, Sean Burnett and Drew Storen combined for two-hit relief, with Storen pitching a 1-2-3 ninth for his fourth save in five chances.
The loss dropped Atlanta three games behind Philadelphia, which beat Florida 10-5 on Wednesday, in the NL East.
Atlanta lost two of three to Washington, only the second series in 24 at Turner Field this year the Braves lost (19-2-3). Atlanta split four games against St. Louis during a 3-4 homestand but still has the major leagues' best home record at 52-23.
Maxwell was hitting only .132 (10 for 76) with six RBI before his drive off Mike Minor (3-1) stayed inside the left-field foul pole and went about 10 rows deep. It was just the third homer of the season for Maxwell and ninth of his big league career -- but he has three slams in four career at-bats with the bases loaded.
Maxwell said he wasn't thinking of his success in bases-loaded situations. "I was just trying to put the ball in play," he said.
Washington manager Jim Riggleman termed the 27-year-old "a work in progress."
"I think he knows he can hit," he said. "He has a few grand slams. He's not afraid of the situation."
Minor said Maxwell hit a fastball. Minor noticed a drop in velocity on his fastball to 90 mph in recent starts, down about 2 to 3 mph from where it should be early in games.
"It was my fault," Minor said. "I threw him two fastballs right there. The second one, he got. It was more middle in. That's what he's looking for in that situation."