The loss broke Washington's four-game winning streak and dropped its record to 32-69, the worst in baseball.
It was a game in which Washington received inconsistent pitching. Right-hander Garrett Mock started for the Nationals and lasted five-plus innings and gave up four runs on eight hits.
For weeks, the Nationals would often talk about how Mock dominated the Minor Leagues as a starter for Triple-A Syracuse. He was 5-1 with a 2.65 ERA. But that success hasn't transferred to the big league level in three starts.
"Other than the obvious, it is the Major Leagues," interim manager Jim Riggleman said. "The talent level is far superior, but competition he is going against is the No. 1 thing. He just hasn't gotten over that hurdle yet. I know he is a confident guy, but he just hasn't been able to finish the hitters off at certain times, but it's in there. I think hitters will tell you this guy is not a lot of fun to hit against. I think the results will eventually show us that."
Mock was given a 4-0 lead after two innings, but he started to unravel in the third. With one out and a runner on first, Ryan Braun's drive to center field was initially called a two-run home run, but the umpires huddled and retreated to the tunnel behind home plate for a quick review. After only a minute or two, they emerged with a new call -- RBI triple.
"It was the right call," Nationals center fielder Nyger Morgan said. "The ball was in my glove. The way I hit the wall, it [knocked] it out [of the glove]. I tried to make a good play. I expected to catch it, but I didn't catch it."
It really didn't matter that the call was overturned, because Braun scored the second run for Milwaukee on a wild pitch by Mock.
"We were still going to be in trouble because Braun is going to be on third," Riggleman said. "So now Prince [Fielder] is going to be up. There is a chance they are going to score that run. Yet, [Mock] got Prince out, and the run scored anyway because of the ball that got past [catcher Josh] Bard. It almost paid off. It almost saved us a run, but that didn't quite cut it."
Mock didn't quite cut it on the mound either. In the fourth inning, Mike Cameron hit a solo home run to make it a 4-3 game.
"I made a bad pitch to Cameron, who did what he was supposed to do with it," Mock said.
But the Nationals took a 5-3 lead when Ryan Zimmerman singled to center off left-hander Manny Parra to drive in Cristian Guzman.
Washington had Parra on the ropes for most of the game, but he managed to get the victory by pitching six innings and giving up five runs on nine hits. Two of the five runs were scored on bases-loaded walks.
"Early in the game, he was walking a lot of people and we took advantage of that," Zimmerman said. "We made him throw the ball in the zone. We were patient. But he settled down and started throwing strikes."
Said Parra about his outing, "I have to get better at the walks and the number of pitches, but these guys got to two strikes -- I don't know how many times they got to two strikes tonight -- and it seemed like they were just going to wait. ... It took a lot of pitches out of me, but thankfully kept us in the game."
It was all Brewers after that. In the sixth inning, with Tyler Clippard on the mound, Corey Hart came home on a double-play ball hit by J.J. Hardy. The run was charged to Mock.
"I think everybody with the Nationals' jersey, including myself, felt like we were in a good spot, but I didn't do my job," Clippard said.
Two batters later, Casey McGehee hit a two-run, pinch-hit homer to give Milwaukee the lead for good. According to Clippard, his biggest mistake in the inning was walking Mike Rivera, who scored on McGehee's home run.
"McGehee beat me on my best pitch," Clippard said. "It never should have gotten to that. Walking Rivera killed me."
Bill Ladson is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.