The NL East champion Washington Nationals secured home-field advantage throughout the postseason by beating the Philadelphia Phillies 5-1 Wednesday for their majors-high 98th victory, with Ryan Zimmerman homering moments after the Teddy Roosevelt mascot won the Presidents Race at Nationals Park for the first time.

Greg Fiume, Getty Images

By winning their regular-season finale, the Nationals clinched top seeding for the NL playoffs and will open on the road Sunday at the winner of Friday's wild-card game between Atlanta and St. Louis. Game 2 will also be at the wild-card winner's stadium, before the best-of-five series shifts to Washington.

Before Wednesday's game, the Nationals were fitted for hats with postseason patches.

The Phillies finish their season with an 81-81 record.

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