"Sin City: A Dame to Kill For", the sequel to the 2005 fanboy favorite, took in just $6.5 million, good for eighth place at the weekend box office.
The opening is well below expectations, with analysts having anticipated a No. 1 debut of at least $15 million, and a quarter of the $29.1 million that the first “Sin City” made in 2005.
"Guardians of the Galaxy" reclaimed the No. 1 position with $17.6 million. The film has done $251.9 million since its Aug. 1 release, making it summer's biggest hit.
"Teenage Mutant Ninja Turtles" claimed the second spot with $16.8 million.
"If I Stay", the young-adult adaptation starring Chloe Grace Moretz, took third with $16.4 million.
The comedy "Let's Be Cops" was fourth with $11 million.
Sports drama "When the Game Stands Tall" rounded out the top five with $9.1 million.