There’s some debate about whether “Uncle Drew’’ is the first feature film based on a commercial — remember “Ernest Goes to Camp,’’ featuring Ernest P. Worrell, the TV pitchman played by comedian Jim Varney? — but there’s no doubt it’s the most successful.

The movie starring Celtics guard Kyrie Irving as a septuagenarian who also happens to be a legendary playground basketball player, did better than expected at the box office in its opening weekend, racking up $15.5 million from 2,742 theaters. And the movie, costarring Shaquille O’Neal, Chris Webber, Reggie Miller, Lisa Leslie, and Nick Kroll, did well despite mixed reviews.

“Uncle Drew’’ is based on a series of Pepsi commercials that, thanks to a clever idea and Irving’s considerable following, went viral.

MARK SHANAHAN