On Jayson Werth’s first day in Washington, back in the winter before his long first season here, he went to a Capitals game. He looked around and saw Verizon Center packed to the rafters. Someone told him that a few years before, it had been empty and dead.

“So I knew that a winning ballclub would bring the fans,” Werth said Thursday night. “And here we are, two years later, and they’re showing up. And it’s awesome.”

Werth spoke at a podium, sandwiched between his two blonde-haired sons, minutes after the best at-bat of his career. He had crushed a walk-off homer to cap a 13-pitch at-bat, his 14th career postseason home run and his new favorite. He had saved the Washington Nationals season, sending them to a 2-1 victory over the St. Louis Cardinals and into Game 5 of this National League Division Series.

“That’s the way the game should have ended,” Manager Davey Johnson said. “Jayson Werth hitting a home run.”

In December 2010, Werth signed a seven-year, $126 million contract to leave the four-time NL East champion Philadelphia Phillies for the Nationals, who had lost 298 games in the past three seasons. Last year, he hit .224, drawing boos from his own fans and derision from across the sport.

This season, even after he missed three months with a broken wrist, his vision for the Nationals and for himself came to fruition. He moved into suburban Virginia, the first time he’s living year-round close to where he plays. The Nationals won 98 games. And, after he crushed Lance Lynn’s 13th pitch into visitor’s bullpen, he brought them one game from the NL Championship Series.

“I feel great for him,” owner Mark Lerner said. “He’s been under a lot of pressure. This is the moment he wanted. He wanted to take this team to a higher level. Not only is he doing the job in the clubhouse, but that’s what it’s all about. I was thinking, ‘This is his moment’ before he even did it.”

When Werth signed with the Nationals, he had listened to the pitch from General Manager Mike Rizzo and owner Ted Lerner and his own agent, Scott Boras. He bought into it in full – the Nationals were going to win and win big. Werth repeated the refrain all winter and all spring: The Nationals’ young talent and his experience would lift them to the top of baseball.

The baseball world mocked him. His outward style did him no favors. He conceals his face with his beard and sunglasses. He does not suffer fools, and he can be taken as surly. Inside his own clubhouse, even through his worst slump, he is beloved and admired.

“Jayson comes across as a gritty kind of, I don’t want to say not likeable – but he’s a gamer,” third baseman Ryan Zimmerman said. “He’s in there all the time. He’s no-excuses, things like that. For him to go through what he went through last year after coming over and signing the big deal and people kind of being negative about him, for him to finally get this moment, the guys in this clubhouse can tell you how much he means to this team. Obviously, the fans can’t really see that all the time, so they don’t really value him as much as we do. But they should now.”

One example came this year, as he returned in early August from his broken wrist. The Nationals’ offense had gone through an ongoing makeover as players landed on the disabled list and came back. Werth and Johnson recognized the Nationals may function best with him at the top of the order, using his considerable ability to reach base to set up teammates for RBI. Big-ticket free agents rarely hit anywhere but the middle of the order. Werth gladly hit at the top.

“A lot of people wouldn’t do that,” Zimmerman said. “They would say, ‘You pay me all this money. I want to hit fifth.’ He’s been receptive to everything. You could to give him credit. Whatever they told him to do, he’s been successful at it. Him moving to that leadoff spot is a huge reason that offense took off.”

In September, Werth said one thing he liked about the switch to leadoff is, “it seems like the lineup always flips over the end of the game.” Think about it: If Werth hit anywhere but first, it would have been some other hitter walking to the plate to lead off the ninth last night.

“If he wasn’t such a selfless ballplayer, he wouldn’t have been in that situation,” shortstop Ian Desmond said. “Halfway through the year, when he accepted the leadoff role. Without a problem, he said ‘I’ll do it.’ If he doesn’t do that, if he fights it, somebody else is hitting right there.”

Instead, it was Werth. He smashed a 96-mph fastball off the back wall of the left field bullpen. Nationals Park came unglued. He leapt into a pile of teammates and stomped both feet on home plate. Afterward, a reporter asked if the moment had made it all worth it.

“We’ll see how things go tomorrow,” Werth said, smiling in a way that gave away the answer.