His episode won in the Best Dramatic Presentation, Short Form category. It beat 4 other nominations including two other Doctor Who episodes: The Girl Who Waited by Tom MacRae and A Good Man Goes To War by Steven Moffat.
When receiving the award, Gaiman said: Gaiman said: “Only a fool or a mad man would try to do it again . . . so I’m on the third draft.”
This is the 6th Hugo award that Doctor Who has won since its revival in 2005.