Showtime “knowingly failed to disclose that its system was defective,” suit says.

Showtime was hit with a federal class-action lawsuit amid reports that it delivered shoddy or non-existent $99 streams of the Floyd Mayweather-Conor McGregor fight Saturday. This is contrary to Showtime's promise of 1080p resolution at 60 frames per second.

"Instead of being a 'witness to history' as defendant had promised, the only thing plaintiff witnessed was grainy video, error screens, buffer events, and stalls," declared the lawsuit (PDF) filed in federal court on behalf of a Portland man named Zack Bartel. The suit seeks to represent "thousands of other consumers" unable to stream the Mayweather fight in HD as Showtime advertised.

Defendant intentionally misrepresented the quality and grade of video consumers would see using its app, and knowingly failed to disclose that its system was defective with respect to the amount of bandwidth available, and that defendant’s service would materially fail to conform to the quality of HD video defendant promised.

Bartel bought the service from the Showtime pay-per-view app to stream on his Apple TV, the suit said.

The fight was delayed at least 30 minutes Saturday night "due to overwhelming traffic." Hundreds of fans took to Twitter to complain.

Showtime said in a statement that it would offer a full refund to aggrieved boxing fans who purchased the fight on its Showtime PPV app. Showtime said fans who experienced streaming problems but ordered the fight from their cable or satellite providers were encouraged to deal with those companies to voice their complaints.

The fight is expected to generate up to a $1 billion in pay-per-view revenue. Mayweather won in the 10th round on a technical knockout.

Showtime spokesman Chris DeBlasio said, "We have received a very limited number of complaints and will issue a full refund for any customer who purchased the event directly from Showtime and were unable to receive the telecast."

The suit claims unjust enrichment and unlawful trade practices. It seeks unspecified damages and legal costs.

Meanwhile, Saturday's match was pirated by an estimated 2.93 million viewers from 239 illegal broadcasts, Variety said.