New Line Cinema's IT remake gave the sagging box office a much-needed jolt after the worst summer season in 11 years, pulling in a massive $123.4 million, which even came in $6 million higher than the original estimate of $117.1 million. The tally easily set a new record for the highest September opening weekend in history, along with the highest debut for any horror movie in history, and provided even more proof that audiences are hungry for edgy R-rated fare. This weekend, Pennywise and The Losers Club will go up against three new movies opening in wide release, Lionsgate's action-packed adaptation American Assassin, Paramount's bizarre drama mother! and Open Road Films' thriller All I See Is You. None of these movies are expected to give IT a serious run for the box office crown, with the movie easily expected to repeat atop the box office with $66.2 million.

What's ironic about that projection is, while it's roughly 50% less than last weekend's epic total, it is basically the same figure that most box office estimates predicted for the opening weekend, not the second weekend. Armed with impressive IT movie reviews (86% Fresh on Rotten Tomatoes), and plenty of buzz, this Stephen King adaptation managed to double the total of most box office estimates, already managing to earn almost four times its $35 million budget in just one weekend. Still, some fans were surprised that this Stephen King adaptation took off, while his big summer movie The Dark Tower managed to severely disappoint, taking in just $48.9 million domestic and $107.3 million worldwide, as one of the many box office underperformers of the summer season.

RELATED: Cary Fukunaga's Canceled IT Reboot Was More Like The Shining: 'That Was the Disconnect'

Box Office Mojo reports that American Assassin, based on the long-running series of Vince Flynn novels, starring Dylan O'Brien as Mitch Rapp, will debut in more than 3,000 theaters this weekend, while mother!, starring Jennifer Lawrence and Javier Bardem, will debut in roughly 2,500 theaters, although no theater estimates were given for All I See Is You. We're predicting that American Assassin will debut in second place with a solid $19.8 million, followed by mother! in third place with $12.6 million, All I See Is You in fourth place with $6.1 million and Home Again rounding out the top 5 with $5.7 million. While September is traditionally not the month for summer-style box office blockbusters, IT is proving that anything is possible, as we head into the fall season with more Oscar-bait movies.

American Assassin tells the story of legendary CIA agent Mitch Rapp (Dylan O'Brien). Long before he began hunting terrorists, Rapp was a gifted college scholar/athlete. Then, tragedy struck and Rapp was recruited into the nation's most elite covert operations program. After completing training designed to teach the kind of lethal skills necessary to target our most dangerous enemies, here and abroad, he is a man reborn with a mission of retribution. The supporting cast is rounded out by Michael Keaton as the man who trains Mitch Rapp, Stan Hurley, with Sanaa Lathan playing his CIA handler Irene Kennedy and Taylor Kitch playing Ghost, the former operative Mitch has been tasked with stopping.

mother! follow's couple's (Jennifer Lawrence and Javier Bardem) relationship, which is tested when uninvited guests arrive at their home, disrupting their tranquil existence. While fans haven't seen much of the supporting cast members in any of the trailers, the cast also includes Ed Harris, Michelle Pfieffer, Brendan Gleeson, Domhnall Gleeson, Jovan Adepo, Emily Hampshire and Kristen Wiig. Darren Aronofsky directs this bizarre film from his own original screenplay, with Scott Franklin and Ari Handel producing.

All I See Is You follows a blind woman's relationship with her husband. It changes when she regains her sight and they discover disturbing details about themselves. Gina (Blake Lively) is a beautiful young woman who's still haunted by the accident that took her sight years earlier. Living in Bangkok with her husband, James (Jason Clarke), she undergoes a cutting-edge operation that restores the vision to her right eye. Now that Gina can see again, she slowly starts to realize that her newfound independence makes James feel jealous, threatened and insecure. Marc Forster directs the dramatic thriller, with a supporting cast that includes Yvonne Strahovski, Danny Huston, Wes Chatham and Ahna O'Reilly.

The top 10 will likely be rounded out by The Hitman's Bodyguard ($2.6 million), Annabelle: Creation ($2.1 million), Wind River ($1.9 million), Leap! ($1.5 million) and Spider-Man: Homecoming ($1.1 million). Also opening in limited release is ArtAffectse' Because of Gracia, Annapurna Pictures' Brad's Status, Film Movement's Time to Die, Abramorama's Wetlands, FilmRise's Vengeance: A Love Story, the independent western Justice! and Vertical Entertainment's The Wilde Wedding. It isn't clear if any of these films will expand nationwide in the weeks ahead.

Looking ahead to next weekend, three new movies will arrive in wide release, 20th Century Fox's Kingsman: The Golden Circle, Warner Bros.' The LEGO Ninjago Movie and Entertainment Studios' Friend Request. Also opening in limited release is the Fox Searchlight sports drama Battle of the Sexes, Oscilloscope Pictures' documentary Bobbi Jene, Vertical Entertainment's horror movie Happy Hunting, Samuel Goldwyn Films' drama The King's Choice, Indican's action movie Ribbons, Roadside Attractions' drama Stronger, Shout! Factory's dramatic comedy The Tiger Hunter, the independent documentary Unrest, Focus Features' drama Victoria and Abdul and A24's dramatic thriller Woodshock. Take a look at our box office projections for the weekend of September 15, and check back Sunday for the box office estimates.