UPDATE 8/24/2014 10:40 AM PT: According to the weekend estimates at Box Office Mojo, "Guardians of the Galaxy" -- as expected -- has reclaimed the No. 1 spot at the box office this weekend, following two consecutive weeks of "Teenage Mutant Ninja Turtles" on top.

"Guardians" looks to end the weekend with $17.6 million, adding to its $251.9 million domestic gross. "Ninja Turtles" netted an estimated $16.8 million, bringing that film's domestic total to $145.6 million. Another comic book-based film further down the chart is the debuting "Frank Miller's Sin City: A Dame to Kill For," with an estimated $6.5 million in its opening weekend.

Originally published Aug. 23, 2014 at 10:48am: Marvel Studios' and James Gunn's "Guardians of the Galaxy" is not only aiming to retake the No. 1 spot at the box office this weekend, but has also set its sights on becoming the No. 1 film domestically for the summer.

According to The Hollywood Reporter, estimates predict the film will end today with about $246 million total -- which is enough to bypass the summer's current domestic box office champ, "Transformers: Age of Extinction." By Sunday, "Guardians" is expected to have brought in $17.8 million over the weekend for a total haul of $251 million domestically.

Looking at 2014 in total, "Guardians of the Galaxy" should be sitting in the No. 3 spot domestically for the entire year at the end of today, behind "Captain America: The Winter Soldier" ($259.7 million) and "The LEGO Movie" ($257.7 million).

While it's inevitable that "Guardians" will take the top spot for the summer, its race back to the No. 1 spot at the weekend box office will be a photo finish. "If I Stay," which opened on Friday, is expected to bring in $17.7 million this weekend. The film, based on Gayle Forman's Young Adult novel and starring Chloe Grace Moretz, was initially expecting an $18 million weekend, but opened slower than expected.

Also at the box office this weekend, Frank Miller and Robert Rodriguez's "Sin City: A Dame to Kill For" opened to $2.6 million on Friday and is now projected to bring in $8.5 million over the weekend. That's down from the $15 million it was projected to bring in earlier this week and a long way from the $29.1 million the first "Sin City" film made during its open weekend in 2005.