NEW YORK -- "Thor: Ragnarok" thundered to one of the year's best box-office debuts with an estimated $121 million domestically, proving again -- just as its flexing its muscle -- the might of the Walt Disney Co.

The robust debut for the third "Thor" movie was a welcome shot in the arm for Hollywood and theatre owners who have just suffered through a terrible October at the box office. "Thor: Ragnarok" also bucked the trend of diminishing returns for sequels. The 2011 "Thor" debuted with $65.7 million; 2013's "Thor: The Dark World" opened with $85.7 million.

"In this business, it's not often you see the second and third installments in the franchise outpacing the previous issue," said David Hollis, distribution chief. "You don't expect never-ending returns when it comes to sequels but it definitely speaks to the quality of the talent at the Marvel Studios team and the way they're thinking about each film out of the gate."

The weekend's other new nationwide release, STX Entertainment's "A Bad Moms Christmas," opened with $17 million over the weekend and $21.6 million since opening Wednesday, according to studio estimates Sunday. The holiday-themed sequel, which returns stars Mila Kunis, Kristen Bell and Kathryn Hahn, came in shy of the 2016 original's $23.8 million opening.

But the big story was "Thor," which also grossed $151.4 million in its second week of international release. The film has, in 10 days, made $427 million worldwide.

Disney isn't alone in being able to roll out such blockbusters but three of the year's five $100 million-plus releases are theirs. (Disney's other two are "Beauty and the Beast" and "Guardians of the Galaxy Vol. 2") The studio has recently, as reported by The Wall Street Journal earlier this week, pushed new terms to theatre owners, saying it will demand a 65 per cent cut of ticket sales for its upcoming "Star Wars" film "The Last Jedi," as opposed to the more typical 60 per cent.

Hollis declined to discuss the studio's negotiations with theatres but said, "We're hopeful that our big films will help drive our mutual success."

The Los Angeles Times also said Friday that Disney barred its critic from attending "Thor: Ragnarok" after the paper published an investigative report about Disneyland's business ties with the city of Anaheim. In a statement Friday, Disney said that the two-piece report showed "a complete disregard for basic journalistic standards."

But the issue of revenue splitting is an acute one for theatre owners who are already fighting against up-and-down ticket sales and mounting competition from streaming outlets. Disney plans to launch a streaming service in 2019 that will include some film releases.

It's often been feast or famine this year at the box office. August was historically dismal, September swung to record-breaking highs and October again badly slumped with the lowest overall gross in a decade. The year is running down 4.8 per cent off last year's record pace according to comScore.

Paul Dergarabedian, senior media analyst for comScore, expects to November will, thanks to "Thor," Warner Bros.' "Justice League" and the Disney-Pixar release "Coco," swing back up.

"It's like a tennis match. We're up. We're down. It's not for the faint of heart," said Dergarabedian. "The industry has its work cut out for it to make up that nearly 5 per cent deficit as we hit the home stretch of what has been an incredibly volatile box-office year."

The huge "Thor" opening also cements the unlikely breakthrough of New Zealand director Taika Waititi, who shepherded the $180 million production to Marvel's best reviews since 2008's "Iron Man." The movie scored a 93 per cent fresh rating from Rotten Tomatoes and an "A" CinemaScore from audiences.

Waititi, 42, is a veteran of the cult comedy series "Flight of the Concords" and has previously directed largely offbeat irreverent indies like the deadpan vampire tale "What We Do in the Shadows" and the oddball outlaw comedy "Hunt for the Wilderpeople."

But the makers of some franchise tentpoles have increasingly turned to more irreverent filmmakers to lend their blockbusters a more comic swagger. The results have been mixed. Phil Lord and Chris Miller departed the stand-alone Han Solo film after creative disagreements, as did original "Ant-man" helmer Edgar Wright.

Yet "Thor: Ragnarok," from a screenplay by Eric Pearson, had no such troubles in returning Chris Hemsworth in the titular role along with franchise regular Tom Hiddleston as Loki. Also brought in was Mark Ruffalo's Hulk, Tessa Thompson as Valkyrie and Cate Blanchett, as the film's villain, Hela.

Several films opened in limited release, including Greta Gerwig's coming-of-age tale "Lady Bird," with Saoirse Ronan. On four screens in New York and Los Angeles, the A24 release drew some of the most packed theatres of the year with a $93,903 per-screen average.

Rob Reiner's "LBJ," with Woody Harrelson, debuted with $1.1 million in 659 theatres. Richard Linklater's "Last Flag Flying," with Bryan Cranston, Steve Carell and Laurence Fishburne, brought in a per-screen average of $10,500 in four theatres.

Estimated ticket sales for Friday through Sunday at U.S. and Canadian theatres, according to comScore. Final domestic figures will be released Monday.

1. "Thor: Ragnarok," $121 million ($151.4 million international).

2. "A Bad Moms Christmas," $17 million.

3. "Jigsaw," $6.7 million.

4. "Tyler Perry's Boo 2!" $4.7 million.

5. "Geostorm," $3 million.

6. "Happy Death Day," $2.8 million.

7. "Thank You For Your Service," $2.3 million.

8. "Blade Runner 2049," $2.2 million.

9. "Only the Brave," $1.9 million.

10. "Let There Be Light," $1.6 million.