Aaron Hicks doubled in the first and scored on a Giancarlo Stanton single. Fedde then retired six batters in a row.
Adam Eaton added a single in the third.
After three innings, Fedde has allowed only two hits, both in the first frame.
The Nats and the Yankees are tied at 1-1.
Update: The Nats took the lead in the fourth inning thanks to a Rendon double and a Reynolds sacrifice fly to center field.
But in the fifth, with a man on, Aaron Hicks launched a two-run shot, his ninth of the season, to give the Yankees the lead. But Fedde got out of the inning when Didi Gregorious was caught stealing at second base on thanks to a great throw by Pedro Severino.
Mid-fifth, the Yankees lead 3-2.
Update II: Fedde finished 5 1/3 innings, allowing three runs on seven hits with two walks and four strikeouts. He threw 97 pitches, 55 for strikes.
Mid-sixth, the Yankees still lead 3-2.
Update III: The Nats got men on first and third in the sixth, thanks to a walk to Rendon and a hard-hit single to right by Soto. But Mark Reynolds and pinch-hitter Daniel Murphy struck out and Severino popped out to shortstop.
After six, the Yankees lead 3-2.
Update IV: Stanton added a run-scoring double in the seventh.
After seven, the Yankees lAd 4-2.
Update V: Murphy doubled to begin the ninth off of Yankees closer Aroldis Chapman. Severino struck out. Pinch-hitter Michael A. Taylor walked. With two men on, Eaton struck out. Trea Turner drove the ball to deep right field, but it was caught to end the game.
Final score: Yankees 4, Nats 2.