“It” can’t be stopped at the domestic box office, dominating with a second weekend of at least $50 million at 4,103 sites, early estimates showed Friday.

Action-thriller “American Assassin” is heading for a distant second place finish with an opening weekend of about $16 million at 3,154 locations, slightly above expectations. Jennifer Lawrence’s horror film “Mother!” should match forecasts and take in about $11 million at 2,368 venues to finish third.

Warner Bros. and New Line are adhering to a $50 million estimate for the weekend for “It,” which means “It” will join 44 other movies that have generated that much in their second weekends. More bullish estimates Friday placed the blockbuster in the $55 million to $60 million range. If “It” makes it to $60 million, it will become the 21st movie to reach that mark in its second weekend.

“It” will wind up on Sunday with a sensational 10-day total of at least $210 million. On Thursday, “It” took in $7.2 million at 4,103 sites, setting a record for a horror film on that day of the week, for a first-week gross of $158.7 million.

“American Assassin,” a joint production between CBS Films and Lionsgate, is an adaptation of Vince Flynn’s 2010 novel of the same name, starring Dylan O’Brien as a CIA black ops recruit trained by a Cold War veteran played by Michael Keaton.

Paramount’s enigmatic horror-thriller “Mother!” is opening in the wake of screenings at the Venice and Toronto film festivals. “Mother!,” helmed by Darren Aronofsky, is a low-risk proposition with a $33 million price tag. The story involves a married couple, portrayed by Lawrence and Javier Bardem, dealing with two strangers — played by Ed Harris and Michelle Pfeiffer — at their tranquil country home.

But the power of “It” may have dimmed prospects for “Mother!” Paramount decided in July to move the “Mother!” release date forward by a month from Oct. 13 but did not offer any explanation at the time.

“Paramount’s decision to move ‘Mother!’ to the week after the debut of ‘It’ from an original date that put it head-to-head with Blumhouse’s ‘Happy Death Day’ was a bit of a ‘pick your poison’ kind of scenario…either way, they were going to have to deal with competition from another film in the horror category,” said Paul Dergarabedian, senior media analyst at comScore.

“The good news is that ‘Mother!’ is a decidedly different, more of an art-house type of horror entry,” he added. “A film shrouded in mystery and playing to an older crowd allows ‘Mother!’ to play to its strengths including a strong talent pedigree in front of and behind the camera and as such was never pre-destined to have the kind of across-the-board appeal of ‘It.'”

Year-to-date total domestic box office has hit $7.8 billion as of Sept. 13, 5.5% behind the same point last year, according to comScore. The percentage decline had been at 6.5% before “It” opened.

Critical support for “It” has been stellar, earning the film an 85% “fresh” rating on Rotten Tomatoes, while “Mother!” has generated a solid 74% score, and “American Assassin” has a disappointing 41% rating.

Online ticketing service Fandango reported that, as of Thursday, second-week sales for “It” are the best the company has seen for any horror movie, and nearly double the second frame receipts of the next closest horror title, “Get Out.”