"That's why we have the home-field advantage," shortstop Ian Desmond said. "We earned it. We were the best team in baseball for a reason."
The big payoff comes now: Game 5 and everything on the line at Nationals Park, with the survivor moving on to engage the Giants in the NL Championship Series.
Gio Gonzalez, Washington's 21-game winner, takes the ball for the Nats against the Cardinals' Adam Wainwright. It's a rematch of Game 1 taken by Washington, 3-2, even though Gonzalez struggled with the strike zone (seven walks in five innings) and Wainwright was dominant (10 strikeouts in 5 2/3 innings).
The Nationals are banking on drawing on more of the emotion the home crowd supplied during a taut Game 4 decided by one Jayson Werth swing against Lance Lynn.
"It seems like the last two months, our crowd here has been electric," Nats manager Davey Johnson said following Thursday night's 2-1 walk-off win courtesy of Werth's home run. "And it translates to the players. We feed off it.
"You know, my guys like playing for a packed house. And they were upon their feet, waving those red flags -- and giving us red instead of white.
"It was fun, and really for me, I don't get excited too much, but I was excited to see the crowd."
Johnson was especially excited, he might have added, to see how crazy the fans went as Werth made his triumphant tour around the bases, leaping on home plate into a crush of teammates.
As dramatic as this Game 4 victory was, Johnson knows as well as anyone that they start Game 5 all even at 8:37 p.m. ET on TBS.
The Nationals are riding the emotions of the first home postseason victory by the franchise since it resided in Montreal in 1981. The nation's capital hadn't hosted a Major League postseason game since 1933 prior to Wednesday.
This is familiar turf for the Cards, who faced elimination games four times in the postseason last season and prevailed each time -- twice against the Phillies in the NLDS and twice in the classic World Series against the Rangers.
St. Louis also had the mettle to seize the first Wild Card game to gain entry into the NLDS, beating the Braves in Atlanta.
"Just like last year," manager Mike Matheny said when asked how his team will respond to the Game 4 loss. "We've had a large amount of heartbreakers this year, and I think that's really been used to develop the character of this team and the resiliency.
"These guys realize that we've got an opportunity to come back and play another game. They do shed it pretty quick. It's a tough one, but we're still alive to play another game."
All hands are on deck in winner-take-all games such as this.
"It's what you play all season for," Werth said, "and what you work out all winter for and what you get to Spring Training early for. We have a chance [Friday night] to take the next step.
"I know my teammates will be ready -- and the city will, too."
While the Nats are new to all of this as a group, Werth has tasted championship bubbly with the Phillies.
"This team we've got here is as close-knit a group as I've ever played with," Werth said. "We've got great team chemistry, and it's a great place to come to the park every day."
The Cardinals feel the same way about one another, and they'll be using their own recent history to guide them through this latest survival test.
"The crowds are louder, pitchers take every pitch more seriously," David Freese, the 2011 World Series MVP, said of the higher pitch of the playoffs. "It's different than anything you've been involved in. The postseason affects everybody differently.
"You've got to come to the yard ready to go."
An 18-game winner as a starter in the regular season, Lynn moved to the bullpen for this series with Wainwright, Jaime Garcia -- now off the roster because of an injury -- Chris Carpenter and Kyle Lohse in starting roles.
Lynn -- who said he challenged Werth with his best pitch, a fastball, "and he just beat me" in Game 4 -- clearly would love to get back on the mound in Game 5 with redemption in mind.
"We've been in plenty of these winner-goes-on, loser-goes-home games," Lynn said. "It's exciting. This is going to be exciting for everybody.
"Gio's a good pitcher. We have one of our horses [Wainwright] going, and they've got theirs. This is what you play for, games like this."