A big heavyweight clash with big implications will have a huge crowd to witness it.

Anthony Joshua’s unification bout with Wladimir Klitschko shattered the previous box office record at Wembley Stadium in London with over 80,000 tickets sold for the April 29 bout, Matchroom Boxing announced on Monday. Joshua will make his third defense of his IBF title while trying to capture the vacant WBA strap.

A second set of tickets was released lunchtime on Monday and scooped up within an hour’s time, according to a press release. The volume of tickets surpassed the previous record set by Carl Froch’s super middleweight championship rematch with George Groves in 2014 at Wembley.

“The demand for tickets for Joshua vs. Klitschko is phenomenal,” promoter Eddie Hearn said in the release. “This is unquestionably the biggest fight in British boxing history and we would have sold out Wembley twice over.” Now, Hearn plans to see if the dimensions of the stadium can be increased to satiate the public’s demand for even more tickets.

“We have put a request in to Brent Council, the Mayor’s office and TFL to increase the capacity by a further 5,000 tickets,” he said. “We are confident of a positive answer and we will release further news shortly. Roll on April 29!” The card will be broadcast locally on Sky Sports; HBO and Showtime, which has Joshua under contract, are vying for the U.S. television rights.

Joshua (18-0, 18 knockouts) will take a massive step up in recent competition against the 40-year-old Klitschko (64-4, 53 KOs), who hasn’t fought since he lost his titles to Tyson Fury in November of 2015 in a lackadaisical performance. Fury was unable to follow through with a planned Oct. 29 rematch with Klitschko and citing personal issues, vacated his titles. Now, Klitschko will try to get the WBA strap back against Joshua, whom he once employed as a sparring partner.