“Gran Turismo: Based on a True Story” and “Barbie” are in a dead heat for the box-office crown, with the video game adaptation just edging Greta Gerwig’s pop sensation, according to studio estimates Sunday.

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.