An emotional high in ninth, a demoralizing low in 18th

It was about as uplifting a moment as the Nationals have experienced all season, their injured All-Star infielder coming up to bat with two outs in the bottom of the ninth and in his first at-bat in five days sending a game-tying homer down the right field line that earned him a curtain call from the crowd of 32,775.

Daniel Murphy's dramatic home run represented the kind of moment teams look back at months from now as a highlight of a season that perhaps ends with an even more memorable moment.

"We were all calling it," teammate Max Scherzer said. "We almost knew it was going to happen."

Unfortunately, they all knew something else about Murphy's blast, which didn't win the Nationals' series finale against the Pirates. It only extended it.

"As soon as he hit it, we were like: 'Yeah, we're going to play 16 innings today,'" Scherzer said. "We were wrong. We played 18."

Yes, indeed. They played 18. And at the end of the longest game in club history - matched previously only by a heartbreaking loss to the Giants in the 2014 National League Division Series - the Nationals were left to wonder what might have been after ending up on the wrong end of a 2-1 decision.

If Murphy's ninth-inning homer was the emotional zenith for the Nats, Starling Marte's 18th-inning homer was the emotional nadir. That it came on a pitch that didn't even have to be thrown only made it worse.

As Marte stepped to the plate with two outs in the top of the 18th, manager Dusty Baker looked into the opposing on-deck circle and saw pitcher Jon Niese. The Pirates were out of players. Niese was going to have to bat.

But Baker wasn't able to relay his sign to catcher Wilson Ramos to have pitcher Oliver Perez intentionally walk Marte until it was too late. Perez threw a first-pitch strike to Marte, and the Pittsburgh cleanup man crushed it deep to left for the decisive homer.

"That was my fault, because I didn't put the fingers up soon enough to walk him," Baker said. "And before I could, he hit the first pitch out of the ballpark. I knew they were out of men. I knew they were out of position players. I knew they were out of pitchers. Just like we were. It hurts to make a mistake like that."

Perez, the Nationals' eighth (and last available) pitcher of the game, also recognized the situation but blamed himself for giving up the fateful home run.

"Normally it's a good idea in that case to walk him, or at least consider it," the veteran lefty said through interpreter Octavio Martinez. "But they gave me the opportunity to pitch to him. And in that case, it's my job to know the situation. I tried to make a difficult pitch for the hitter, and unfortunately he was able to make good contact on the pitch. It was my mistake."

The Nationals committed plenty of mistakes throughout this marathon lasting 5 hours, 48 minutes. They didn't give themselves many scoring opportunities - only 12 total men reached base in 18 innings - but they squandered several of those they did give themselves.

They killed potential rallies with inning-ending double plays in the seventh, 10th and 17th innings. They ran into outs in the sixth and 17th innings. They stranded men in scoring position in the first, 14th and 18th innings.

"We just didn't come up with that all-important hit," Baker said. "We had runners in scoring position a bunch of times late. And when it gets late, your concentration level gets less and your energy level is less."

Not that the Nationals did everything wrong. In addition to Scherzer's seven innings of one-run ball, they got 10 innings of scoreless relief before Perez surrendered the game-winning homer. They also pulled off a brilliant defensive play in the 16th, with Michael A. Taylor, Danny Espinosa and Wilson Ramos combining of a perfectly executed relay from center field to shortstop to the plate to nail the Pirates' Eric Fryer and boost everyone's spirits.

"That was awesome," Baker said.

"I love watching plays like that," second baseman Trea Turner said. "Because I think stuff like that goes unnoticed. Everybody's going to talk about the home run to win the game, but Danny's play was pretty special."

So was, of course, Murphy's ninth-inning blast. Sidelined with a sore hamstring suffered in Tuesday's All-Star Game, he emerged off the bench with his team down to its final out, the crowd roaring with approval.

Murphy battled through a tough at-bat with Pirates closer Mark Melancon, fouling off a 2-2 cutter on the inside corner that broke his bat. As he walked back to pick up a fresh piece of lumber, Murphy contemplated the pitch he just saw and fought off and prepared to see another one.

"The nicest thing was, he made his pitch and I didn't roll it over to the first baseman," he said. "I ended up fouling it. It's always nice to be able to make a move on a pitch and make an adjustment from there. He made a really good pitch, and I was able to get rid of it. I think it was able to help me prepare for the next cutter that he threw, the next pitch."

That next pitch from Melancon was lower, but not low enough. Murphy, as he has done so many times in the last calendar year, turned on the low-and-inside pitch and drove it down the right field line, inside the foul pole for the home run that turned a previously downtrodden ballpark into joyous celebration.

"This was MVP-caliber," Baker said. "And in my mind, he's having an MVP season. That was big. Especially off a guy like Melancon, who's an All-Star and a very good pitcher."

Scherzer expected it to happen. Did Murphy?

"That makes one of us," he insisted. "I didn't expect to take him deep, not with the kind of year he's having. He's having a great year. I was fortunate to get a good swing off. I wish it would've come in a win."

Indeed, when Niese struck out Espinosa nearly three hours later to wrap up the longest regular season game in club history, Murphy's earlier heroics lost some of their significance.

That homer may yet be remembered by the Nationals, but on this day it only gave them and their fans momentary hope, hope that would be dashed much, much later in the evening.