Cincinnati’s Drew Stubbs slides under the tag of Danny Espinosa to steal second base in the third inning Friday. (Toni L. Sandys/The Washington Post)

Jayson Werth, the antihero trying to win over Washington, insists he does not think about his first season with the Washington Nationals. “Last year’s over,” he said. When he stepped into the batter’s box Nationals Park after 11 p.m. on Friday night, the bases loaded and one out in the 13th inning, he had an opportunity to win the game and to convince the rest of the world this is a new year.

A few minutes later, Werth jogged down the first base line and tossed his black bat to the ground. His game-winning single had lifted the Nationals to a 2-1, 13-inning victory over the Cincinnati Reds, their fourth straight win and second straight walk-off in extra innings.

Their dearth of offense does not bode well for their future success, their rotation’s win-loss record or the heart condition of their fans. But it did not prevent them from sending what remained of the 26,959 at Nationals Park home celebrating another dramatic victory, which improved them to 6-2. The Nationals remained in first place in the National League East, and they did it on Werth’s first walk-off RBI with Washington.

“You want to be a part of those,” said Werth, who has started this season 10 for 33 with four walks, swinging with more conviction and, by all accounts, finding more comfort with the team. “That’s what you play for. So hopefully that’ll be the first of many.”

Said Manager Davey Johnson: “I think he can just concentrate on being Jayson Werth more so than trying to spread himself thin.This game is tough enough. When you start bearing the burden of teammates and trying to help out . . . I think he doesn’t feel the need to do that this year. I think he’s going to be a lot more focused.”

Late Friday night, the moment demanded focus. Danny Espinosa sparked a rally against lefty reliever Sean Marshall with a broken-bat, infield single with one out in the 13th. Ryan Zimmerman and Adam LaRoche each drew walks, loading the bases for Werth.

The infield shifted, first baseman Joey Votto moving way off the line. Werth considered dropping a push bunt to the right side, then thought better of it. He took a strike and a ball, then whiffed at a high fastball. Marshall threw a 77-mph curveball, and Werth was not fooled. He lined it past drawn-in shortstop Zack Cozart, jogged down the line a few steps and tossed the bat toward the dugout.

“That was, ‘Let’s go home,’ ” Werth said.

Werth continued his slow trot to first, then waited for teammates to mob and let the cheers wash over him. A television reported grabbed him for an on-field interview that blared on the stadium speakers.

“I’m just excited about all these fans that stuck around tonight,” Werth said. “How ’bout ’em?”

Many of those fans had booed him last season. Werth says he is fine with that, that fans will be fans. But he will also live here the next six years.

“I mean, he wants to be liked, just like everyone else,” Zimmerman said. “And I don’t see why anyone shouldn’t like him. He came out every day last year and played different positions, hit in different spots in the order and did a lot of things that a lot of people in his position wouldn’t have been open to do. I think with the injuries and stuff we had last year, he was asked to do a lot that he shouldn’t have been.”

The Nationals’ bullpen played a heroic role, too. Craig Stammen struck out the side for the second straight day in an extra inning, whiffing three of the four batters in the 13th to earn consecutive wins. Tom Gorzelanny pitched two scoreless innings, working around a leadoff double in the 12th inning. Ryan Mattheus, Henry Rodriguez and Brad Lidge, who rebounded from his blown save Thursday, each chipped in a scoreless inning.

Jordan Zimmermann allowed one earned run in seven innings for the second time in two starts, and again reprised his role as a pitcher no offense loves. When he left the game, the Nationals trailed, 1-0, despite his allowing three hits and two walks while striking out three. It became the 13th quality start since the beginning of last year that would net Zimmermann a loss or no-decision. In the last nine games Zimmermann has started, the Nationals have scored a total of 24 runs.

“It’s been tough,” Zimmermann said. “But I knew these guys were going to get a run sooner or later.”

With one out in the eighth inning, Manager Davey Johnson sent left-handed pinch-hitter Chad Tracy to the plate. Right-hander starter Bronson Arroyo had bewildered the Nationals all game while slinging his slop, mid-80s fastballs and every breaking pitch known to mankind. The Nationals had scraped together three hits and a walk and hardly made Arroyo work — his pitch count sat at 94.

But Reds Manager Dusty Baker played the left-right matchup and summoned from his bullpen left-hander Bill Bray. (Yes, Nationals trivia buffs, he was in the 2006 trade that brought over Austin Kearns and Felipe Lopez.) Johnson countered. He pulled back Tracy and tabbed Xavier Nady.

Baker had no choice but to stick with Bray. Nady got ahead in the count, 1-0, and then smoked an 89-mph deep to left field. Ryan Ludwick raced back to the warning track, reached up and his glove, the ball and fence intersected. The ball deflected off something, then trickled into the visitors’ bullpen.

“I knew that [Arroyo coming out] was a possibility,” Johnson said. “The guy was pitching such a strong game. I told [Tracy] when he went up there, ‘If they bring in a lefty, that’s it. But you’re going to get him out of the game.’ That worked out pretty good.”

Johnson had outmaneuvered Baker. Nady, who had no earthly idea where he would play this season before the Nationals signed him March 18, had tied the game and taken Zimmermann off the hook. It allowed Werth to come up for a chance to win the game, to validate his belief this year will be different.

“It’s a crazy game,” Werth said. “And that’s why I love it.”