WASHINGTON -- For more than six seconds, the ball hung in the air, as if the moment were not dramatic enough already. Ryan Zimmerman, an original Washington National now in the twilight of his career, had hammered a pitch to center field as the Nationals were clinging to a one-run lead in the fifth inning of a must-win game.

The wind was wreaking havoc on fly balls. Where this one landed could determine the Nationals' season -- and the rest of Zimmerman's career. Over the fence it went, scoring three runs, buttressing the Nationals' lead in Game 4 of the National League Division Series against the Los Angeles Dodgers and proving a vital cushion in a 6-1 victory Monday night that sends the series back to Dodger Stadium for a winner-takes-all Game 5 on Wednesday.

The 35-year-old Zimmerman, who has played all 15 of his seasons with the Nationals, lifted a chest-high 96.6-mph fastball from Dodgers reliever Pedro Baez high into the air in the fifth inning with the Nationals ahead 2-1. It stayed there for what felt like an eternity and settled 414 feet later, scoring Anthony Rendon and Howie Kendrick, sending the 36,847 fans at Nationals Park into a frenzy and making those who didn't fill the thousands of empty seats at the stadium feel instantaneously silly.

It was a signature moment for a Nationals franchise that still lacks a playoff series victory and will seek its first with Stephen Strasburg on the mound. Zimmerman, long ago nicknamed Mr. Walk-Off, hasn't hit many in recent years as age gnawed at his game.

Big home runs, though? Even in a limited role, Zimmerman is capable of those.

"That's why sports are special," he said. "You can't replicate it."

Had the Nationals lost Game 4, Zimmerman would have hit free agency this winter without a clear read on his future. He is in the final season of a six-year, $100 million contract. The Nationals will almost assuredly exercise a $2 million buyout rather than an $18 million club option.

He could retire and start a five-year, $10 million personal-services contract with the team, though Zimmerman threw cold water on that idea.

"There's been a lot of talk how these are my last games," he said, only to be interrupted by Nationals ace Max Scherzer, whose seven superb innings kept the Nationals in the game long enough for Zimmerman to break it open.

"I really don't think this is his last games," Scherzer said.

"The last game [of the regular season] they tried to give me a standing ovation," Zimmerman continued. "I feel good. We've got plenty to go."

With left-hander Rich Hill starting, Nationals manager Dave Martinez tried to play the platoon advantage with Zimmerman's right-handed bat. He struck out in his first two plate appearances. In the fifth, the Nationals rallied against reliever Julio Urias, taking the lead and putting two on for Zimmerman.

Dodgers manager Dave Roberts countered any right-vs.-left advantage by bringing in Baez. Martinez could have pinch hit with left-hander Matt Adams. He stuck with Zimmerman -- and was rewarded handsomely.

"That was huge," Martinez said. "He understands his role. But he came tonight and got a chance to start and, man, what a huge moment for us. I'm proud of him."

Of all his moments with the Nationals -- making the major leagues in 2005 months after being drafted, hitting a walk-off home run in the first game at Nationals Park in 2008, three other prior division-series home runs -- Monday night's may have been the apex for Zimmerman.

Especially if the Nationals can finally close out a playoff series. Particularly as a wild-card team against the 106-win Dodgers.

"This is why you play the game," Zimmerman said. "This is what you live for."