WASHINGTON -- That season-high five-game winning streak that they owned five days ago seemed like a distant memory by the time the Braves packed their bags and headed out of RFK Stadium on Thursday afternoon.

What appeared to be a four-game series that would only improve their standing among the National League's elite, instead turned into one that left Chipper Jones wondering if his teammates had indeed overlooked the capabilities of the suddenly-hot Nationals.

"Whenever we've needed to up our play, we've been able to do that," Jones said. "Unfortunately, the fact that we lower our level of play against certain teams worries me."

Jones wasn't specifically pointing his fingers at any of his teammates after Thursday afternoon's 4-3 loss to the Nationals. But then again, that wouldn't have been necessary. While losing three times in this four-game set against a team that entered the week with just 12 wins on the season, none of the Braves had to be reminded of the opportunities that they had just squandered.

While they still own the National League's worst record (15-26), the Nationals have won six of their past seven games and five of the nine that they've played against the Braves this year. But Jones didn't want to hear anything about how his team had simply run into a hot team at the wrong time.

"It was all us," said Jones, whose two-run fourth-inning homer gave the Braves an early lead in the series finale. "It had nothing to do with them. You pitch bad, you play bad defense and you don't hit, you're not going to win no matter who you are playing."

Despite losing four of their past five games, the Braves still are just 1 1/2 games out of first place in the NL East standings. But in order to keep that standing, they're going to have to go into Boston this weekend and find a way to avoid the costly middle-inning blunders that led to the losses they suffered in the final two games of this series.

"When our team made mistakes, they took advantage," said Andruw Jones, whose determination to continue guessing, instead of reacting to pitches, led to him going 3-for-16 with six strikeouts during this four-game series.

During Wednesday night's loss, it was Kelly Johnson's fifth-inning error that allowed the Nationals to provide the difference with four unearned runs. The series finale was lost when Chuck James forced manager Bobby Cox to turn the ball over to the suddenly struggling Chad Paronto, whose assignment was to protect a 3-2 lead.

After surrendering a leadoff double to Jesus Flores, James exited the sixth inning with one out and a runner on third. Pinch hitter Dmitri Young greeted Paronto with a game-tying single through the left side of a drawn-in infield. One batter later, the Braves right-handed reliever saw his brief outing end courtesy of Felipe Lopez's game-winning RBI triple off the left-center-field wall.

"It's a been a long seven days," said Paronto, who has allowed five earned runs and seven hits, while completing just 2 2/3 innings in his past five outings.

Meanwhile, the Braves simply didn't produce any offense against the Nationals relievers, who allowed just one run in the 16 innings that they worked during this series. Over the course of those final eight innings, they surrendered just two singles, and both of those came Wednesday night.

During the finale, the Braves gained a 3-1 lead off Nationals starter Matt Chico. But Matt Diaz' two-out fifth-inning RBI single would be their final hit of the afternoon.

"They've got some guys down there [in their bullpen] who have thrown really, really well," Chipper Jones said. "The games that were lost here weren't lost in the seventh, eighth and ninth inning. They were lost in the fourth, fifth and sixth."

James retired the first eight batters he faced and then surrendered inconsequential consecutive two-out singles in the third inning. He then allowed a hit to three of the first four batters that he faced in the fourth. One inning later, the Nationals tallied another run with the shortest RBI single that Austin Kearns may ever produce.

With two outs and the bases loaded, Kearns hit a chopper that found the start of the grass in front of the plate. James raced to make the play. But while attempting to end the inning with an inning-ending tag of Lopez, he never gained control of the baseball.

"For the most part, it comes down to that one play," James said. "If I make that, it's a different ballgame."

Unfortunately for the Braves they are headed into this week's showdown against the Red Sox with plenty of "ifs" dancing through their heads. What if only they had backed John Smoltz with more than one hit in eight innings against Jason Bergmann on Monday? Or what might have happened if Johnson had secured that grounder before Kyle Davies hung that decisive curveball in Wednesday's fifth inning?

Or, what if Johnson, Brian McCann and Jeff Francoeur hadn't combined for just five hits in 38 at-bats during the series?

There wasn't any reason for Cox to look for answers to these questions as he headed to Boston. What had happened was in the past, and for the Braves that might have been the only encouraging thing to draw from a forgettable four-day stay in Washington.

"They were tight games," Cox said. "A couple of guys hit the ball good in this series -- Chipper and [Edgar] Renteria. Outside of that, there wasn't a whole lot happening."