Sony Pictures reported that “Gran Turismo” opened with $17.3 million over the weekend, while Warner Bros. estimated that “Barbie,” in its sixth week of release, took in $17.1 million. Those totals could change when final ticket sales are counted Monday.

Due to a few wrinkles, it’s all but certain that “Barbie” sold more tickets than any other movie Friday through Sunday, even if “Gran Turismo” is claiming the checker flag.

One reason: It was an usual weekend in multiplexes. U.S. movie theaters held the second annual National Cinema Day on Sunday, with $4 tickets to all films and showtimes at nearly all of the country’s theaters.

“Barbie” was expected to be easily the top draw during the discounted day, with a particular boost coming from repeat viewings. With a domestic total of $594.8 million in ticket sales, “Barbie” has passed “The Super Mario Bros. Movie” ($574 million) to become the year’s biggest domestic hit. With $1.34 billion worldwide, “Barbie” will also soon surpass the leading $1.35 million worldwide tally of “Mario.”

National Cinema Day is meant to lure moviegoers to theaters during a typically slow period — and recoup the lost ticket revenue by selling a lot of popcorn. Last year’s event drew 8.1 million moviegoers, making it the busiest day of the year in theaters. Warner Bros. estimated that “Barbie” would gross $7.8 million on Sunday, which would mean almost 2 million people saw the film that day.

So what was the top movie in theaters this weekend?

“Barbie,” says Jeff Goldstein, distribution chief for Warner Bros. “Without any question.”

Though “Barbie” is the weekend’s top draw, “Gran Turismo” has a slight — and somewhat debatable — edge in gross earnings. In its weekend totals for “Gran Turismo,” Sony is also factoring in a hefty $3.9 million from preview screenings held before Thursday, along with $1.4 million in Thursday previews. Such accounting, while common practice for Hollywood, has stretched the definition of an opening “weekend.”

“We’ve made a big issue of it only because ‘Barbie’ has had incredible holds,” says Goldstein. “To take away the number one, which would make it five weekends at number one since it opened, kind of doesn’t feel right for the ‘Barbie’ filmmakers who really deserve the accolades.”

Sony executives declined to comment.

Either way, it’s a so-so start for “Gran Turismo,” which cost about $60 million to make. But the film, about a young man whose love of the PlayStation video game helps turn him into a real-life racer, has gone over well with audiences. Moviegoers gave the Neill Blomkamp-directed movie an “A” CinemaScore.

The ongoing strike by actors and screenwriters has taken away the studios’ ability to promote films with their casts. To help spread the word on “Gran Turismo,” Sony held several weeks of preview screenings and fan events.

“Obviously, every movie is in pursuit of being the number one film,” says Paul Dergarabedian, senior media analyst for data firm Comscore. “But at the end of the day, ‘Barbie’ is just an out-and-out smash global blockbuster. No matter how you slice it, ‘Barbie’ is always going to be a winner no matter the outcome of this weekend. Sony, left without stars to go out and promote the movie, had to rely on the audience becoming the marketing voice.”

Last week’s top film, the DC Comics release “Blue Beetle,” slid to third place in its second week, with $12.8 million. The Warner Bros. film has made $46.3 million in two weeks, making it another misfire for DC.

Christopher Nolan’s “Oppenheimer” trailed in fourth, with $9 million in its sixth week. Like its “Barbenheimer” sibling, the Universal Pictures release has played remarkably well beyond the point at which most films fall off in theaters. “Oppenheimer” has passed $300 million domestically and reached $777.1 million globally.

A handful of other new releases also hit theaters. MGM’s high-school comedy “Bottoms” got off to a strong start in limited release, grossing an average of $51,600 per location in 10 theaters. The Liam Neeson thriller “Retribution” debuted with $3.3 million in 1,750 theaters for Lionsgate and Roadside Attractions.

“The Hill,” a sports drama starring Dennis Quaid, launched with $2.5 million from 1,570 locations for Briarcliff and Open Road. And “Golda,” starring Helen Mirren as the former Israeli prime minister, debuted with $2 million in 883 theaters for Bleecker Street.

According to Comscore, the North American box office is now just $70 million shy of breaking $4 billion for the summer. After an up-and-down season that saw some major releases like “Indiana Jones and the Dial of Destiny,” “The Flash” and “Mission Impossible: Dead Reckoning Part One” fall short of expectations, “Barbie” and “Oppenheimer” have spurred a comeback. If the box office manages to reach $4 billion for the summer, it would be the first time since 2019.

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

1. “Gran Turismo: Based on a True Story,” $17.3 million.

2. “Barbie,” $17.1 million.

3. “Blue Beetle,” $12.8 million.

4. “Oppenheimer,” $9 million.

5. “Teenage Mutant Ninja Turtles: Mutant Mayhem,” $6.1 million.

6. “Meg 2: The Trench,” $5.1 million.

7. “Strays,” $4.7 million.

8. “Retribution,” $3.3 million.

9. “The Hill,” $2.5 million.

10. “Haunted Mansion,” $2.1 million.