Fans come out for knockout artist Joshua against Klitschko

British boxer Anthony Joshua, left, and Ukrainian boxer Wladimir Klitschko take part in their weigh-in at Wembley Arena in London, Friday, April 28, 2017. They are due to fight for Joshua's IBF and the vacant WBA Super World/IBO heavyweight titles on Saturday at Wembley stadium in London. (AP Photo/Matt Dunham) (The Associated Press)

British boxer Anthony Joshua, left, and Ukrainian boxer Wladimir Klitschko take part in their weigh-in at Wembley Arena in London, Friday, April 28, 2017. They are due to fight for Joshua's IBF and the vacant WBA Super World/IBO heavyweight titles on Saturday at Wembley stadium in London. (AP Photo/Matt Dunham) (The Associated Press)

British boxer Anthony Joshua, left, knocks down Ukrainian boxer Wladimir Klitschko during their fight for Joshua's IBF and the vacant WBA Super World and IBO heavyweight titles at Wembley stadium in London, Saturday, April 29, 2017. (AP Photo/Matt Dunham) (The Associated Press)

British boxing fans are turning out in force to cheer on their countryman, Anthony Joshua, in his title defense against longtime former champion Wladimir Klitschko.

Some 90,000 are expected to fill the stadium Saturday night for what has been billed as the biggest heavyweight fight in more than a decade.

The fight matches two Olympic gold medalists (Klitschko 1996, Joshua 2012) who both stand 6-foot-6 and have impressive knockout records. Klitschko, who lost his title in his last fight, will be trying to become a three-time champion at the age of 41 against Joshua, who has fought only 18 times but has 18 knockouts.