The satellite broadcaster said that there was an "issue" with its late phone and online bookings amid "unprecedented demand" to watch the British boxer take on Wladimir Klitschko.
The glitch meant that many fans were unable to complete their £14.95 order to watch the fight in Hamburg, which Haye lost on points.
During the fight, Sky used its Twitter feed to advise those experiencing problems to "please find your nearest pub". The company also said that viewers purchasing the fight on their remote controls were not having any issues.
After the fight, a statement on Sky's Facebook page said: "We are sorry to have disappointed any viewers who were unable to order Haye vs Klitschko [on Saturday]. Sky had an issue during the evening with new telephone and online bookings for the fight.
"We had encouraged early booking over three weeks leading up to the fight, through a range of media including on-air promos and press advertising.
"However, we experienced unprecedented demand on the night and while early telephone and online purchases worked there were issues with late bookings through these routes on Saturday."
Sky replayed the fight yesterday at no extra charge to all customers on Sky Box Office 739 and in high definition on channel 752.
Last June, media regulator Ofcom rapped Sky for promoting a boxing match on Sky Box Office which had actually been cancelled.
Boxing promoter Oscar De La Hoya also criticised the satellite broadcaster in April for refusing to support Amir Khan's title fight on its pay-per-view platform.