Kane Parsons has become the youngest film-maker to open a film at number one at the North American box office for his directing debut Backrooms.

Parsons, 20, is seven years younger than the previous record holder, Josh Trank, who was 27 when his debut Chronicle recorded a $22m opening in 2011. Backrooms stunned industry observers by taking $81m in its first weekend in North America – which was also a record for its studio, A24.

Backrooms, described by the Guardian’s chief critic Peter Bradshaw as “an icily brilliant and genuinely disturbing conceptual horror film” is based on Parsons’ YouTube series of the same name, inspired by the “creepypasta” of the same name, referring to a fictional space of infinite, interconnected spaces.

Parsons’ age has led to claims online that he did not in fact direct the film, with actor Mark Duplass responding: ““Hmmm, with all due respect I don’t remember seeing you on set. When I was there, Kane was 100% in control. More so than many directors 3x his age.” Parsons himself also commented on the rumours, saying: “This is actually all true. They don’t tell you this, but 96% of all movies released in North America and Europe are actually directed by the same person. They call him ‘The Older Gentleman’. He has had all of Hollywood in a chokehold for decades now.”

Backrooms’ box office success follows that of another low-budget horror film, Obsession, directed by Curry Barker. Barker, at 26, is six years older; his film was released on 15 May with a $17.1m opening weekend in North America, and has now recorded $104.7m after four weeks.