Disney's Tron: Ares opened to a paltry US$33.5 million (A$51.47 million) domestically over the weekend, falling short of analyst expectations of $40-50 million.
The sci-fi sequel captured the top spot but delivered half the inflation-adjusted opening of 2010's Tron: Legacy, which debuted to $44 million - equivalent to roughly $65 million today.
That's a significant decline for a film carrying a $180 million production budget before marketing costs.
Friday's $14.3 million haul, including $4.8 million in previews, pushed projections down from the initial $40-$50 million range.
Global opening reaches just $60.5 million
Globally, the Joachim Rønning-directed film reached $60.5 million through Sunday, with $27 million from international territories.
Premium large format screens - Imax, Dolby and 3D - accounted for 67% of ticket sales.
China opens on 17 October, which could provide some upside.
Latin American markets showed promise, with both Brazil and Mexico opening ahead of Tron: Legacy and last year's Alien: Romulus.
But with box office revenue typically split 50-50 between studios and cinema operators, Tron: Ares requires roughly $360 million globally to break even theatrically.
The film received a B+ CinemaScore rating and 56% on Rotten Tomatoes.
Major releases including Wicked: For Good (21 November) and Avatar: Fire and Ash (19 December) will compete for screens over the coming months.
