WASHINGTON -- At some point, hope stops floating. For the Washington Nationals, game No. 150 could well be that point.

Heading into Tuesday night's series opener against the Baltimore Orioles, the Nationals trailed the first-place New York Mets by 6.5 games in the National League East. To make the season-ending Nats/Mets series matter, Washington needed to gain 3.5 games over its next 10 contests. And this was the perfect opportunity.

(Cue the "30 for 30" voiceover guy.)

What if I told you that All-Star center fielder Adam Jones, nursing a sore back among other things, was not in the O's lineup? What if I told you that struggling hurler Ubaldo Jimenez, who has been one of the least effective starters in the American League during the second half of the season, was on the hill? Most importantly, what if I told you that the Atlanta Braves, who've been by far the worst team in baseball over the past two months, actually managed to beat the Mets?

If I told you all that, you'd have no choice but to think that the Nationals would be 5.5 games back on Wednesday morning.

But that simply won't be the case.

Did I mention that Jimenez threw 25 of his first 50 pitches out of the strike zone and walked five batters in the first five innings? Or that the normally sure-handed Orioles, who lead the majors in fewest errors, committed three miscues for just the fourth time this season, with two of the flubs coming in one sloppy bottom of the fourth? Or that All-Star closer Zach Britton, who blew his most recent save opportunity, was conspicuously passed over in the ninth inning for the second time in the past week?

Despite all that, Washington still came up short, falling 4-1 to their neighbors from just up the road in front of a mixed crowd of 27,000-plus that seemed equal parts orange and red.

Gio Gonzalez allowed four runs on six hits in 4 2/3 innings on Tuesday. He struck out six and walked two. Nick Wass/AP

It didn't help that Nats starter Gio Gonzalez gave up six hits in 4⅔ innings, including an RBI single to Jimenez that got the Orioles on the board. Or that the offense picked a bad time to go dormant: On Tuesday, following an eight-game stretch in which they won seven games and averaged double-digit hits, the Nats managed just three base knocks, two of which never left the infield.

It wasn't nearly enough to capitalize on the early control problems of Jimenez, who after walking four in the first three frames, settled down and ended up coming away with his 100th career win.

"He had command of all of his pitches and kept us off balance," said Bryce Harper, whose three walks gave him 117 on the season, a new Nationals record (Adam Dunn had 116 BBs in 2009). "His sinker was pretty good, his curveball was pretty good, his split finger of course is tough."

"He was mixing everything," Nats catcher Jose Lobaton said. "He was nasty."

As a result, instead of Big Sean's "I Don't F--- With You" bouncing off the walls of the home clubhouse, as has been the custom following a Washington win, there were other, less jubilant noises filling up the space following Tuesday's seemingly inexplicable loss: The faint sprinkling of water falling from shower heads onto shower floors. The cracking of wood mallets striking crab legs as several Nationals retreated to the postgame spread in an effort to wash down the bitter aftertaste of an ill-timed defeat. The uncharacteristic sound of players intimating that maybe, just maybe, this loss was different than any the previous 71 that the team had suffered.

"Point blank, we probably can't lose very many games the rest of the year, if any," said Casey Janssen, one of four hurlers who combined to toss 4⅓ hitless innings in relief of Gonzalez. "We know that one or two more losses and it's going to be a real tough hill to climb. Little bit of desperation, little bit of urgency. But you just gotta stay the course."

"It's one of those things where you brush it under the rug, hopefully we try to get on top and get a W and hopefully the Braves slow ‘em down tomorrow," Gonzalez said. "Either way, we gotta do our job and focus on what we need to focus on. Just turn the page on this one and try to move forward."