Top 3 pitching performances in Nats history:
1. John Patterson vs. Dodgers
2. Jordan Zimmermann vs. Marlins
3. Ramon Ortiz almost no-hitter
IMHO- I would put the Aug 15th, 2006 complete game 2-hit shut-out of the Braves by Pedro Astacio in third. I was at both those games and Astacio's stuff was better that day, gave up no runs and pitched a complete game.