Anderson turned aside all 34 shots he faced as the Senators extended their domination of Washington with a seventh consecutive victory over the Capitals.
Braden Holtby made 24 stops for Washington, which is mired in its longest skid since Dec. 2-18, 2010.
The Caps were playing with NHL goals leader Alex Ovechkin (lower-body injury).
Justin Bieber crashes Drake Bell's album release party
Members of Congress to keep receiving porn magazine