The eagerly awaited middleweight title bout between Gennady Golovkin and Kell Brook sold out in just 11 minutes on Friday.
Golovkin, considered by many as boxing's pound-for-pound king, will put his WBA, WBC, IBF and IBO world titles on the line against Sheffield fighter Brook, who is stepping up two weight divisions to take on the ferocious Kazakh at London's O2 Arena on September 10.
And many fans were left disappointed as the demand for tickets saw the O2 box office sell out in just 11 minutes.
"Tickets for the WBA, WBC, IBF and IBO World Middleweight title clash between Gennady Golovkin and Kell Brook sold out in just 11 minutes at The O2 box office today," read a statement from Matchroom Boxing.
"Golovkin and Brook meet at the London venue on September 10 live on Sky Sports Box Office and HBO and fight fans have snapped up the tickets in a heartbeat to see pound-for-pound star Golovkin box in the UK for the first time against the unbeaten IBF World Welterweight champion."
Golovkin is the favourite to retain his titles and is the undisputed king of the middleweight division having won all 35 of his professional fights, 32 of which have come via knockout.
IBF world welterweight champion Brook struggled to find high-calibre opponents willing to face him having dominated at welterweight, and he too takes an unbeaten record into the bout having won 36 fights - 25 by knockout.