Washington got three hits in their first inning but failed to record another the rest of the game, thanks in part to the Major League debut of Tampa Bay rookie Chris Archer.
The 23-year-old Archer shook off his rocky first inning and lasted six in total, striking out seven.
Jose Molina hit a solo homer in the second inning against Strasburg, and the Rays (38-30) added a run in the third but could not find the equalizer.