Little blue Smurfs and not-so-little green men from space are in a photo finish for the No. 1 spot at the weekend box office. Daniel Craig and Harrison Ford's sci-fi Western Cowboys & Aliens and the family adventure The Smurfs both opened with $36.2 million, according to studio estimates Sunday.

"In all my years, I've never really seen a race this close," said Paul Dergarabedian, an analyst for box-office tracker

Captain America: The First Avenger, slipped to No. 3 with $24.9 million. Harry Potter and the Deathly Hallows: Part 2 pulled in $21.9 million to become the franchise's top-grossing chapter at $318.5 million domestically.

For sale

Katharine Hepburn's former home on Connecticut's Long Island Sound is on the market for $18 million, or $28 million for the estate.

The house had 21 rooms and nine bathrooms when the Academy Award-winning actress lived in it until her death in 2003, but it has been reduced to 15 rooms and 71/2 bathrooms.