On Saturday night, Anthony Joshua puts his heavyweight world titles on the line against Oleksandr Usyk. Here is everything you need to know about the fight. A heavyweight world title fight between two of the biggest stars in world boxing as Britain's Anthony Joshua, the WBA, IBF and WBO champion, puts his belts on the line against unbeaten Ukrainian Oleksandr Usyk. Joshua is a two-time heavyweight world champion having <a href="https://www.thenationalnews.com/sport/other-sport/clash-on-the-dunes-anthony-joshua-beats-andy-ruiz-jr-to-regain-world-titles-in-saudi-arabia-1.948220" target="_blank">reclaimed his titles in a rematch against Andy Ruiz Jr</a> in Saudi Arabia in December 2019 following his shock stoppage defeat to the Mexican-American in New York six months earlier. Usyk, meanwhile, is regarded as one of the greatest cruiserweights in history and soon after unifying the division, made the step up to heavyweight. The event takes place on Saturday night with the undercard getting under way at 9pm UAE time. Joshua and Usyk are scheduled to make their ring walks at 1am Sunday morning. The event will be held at the Tottenham Hotspur Stadium - the home of Premier League football club Tottenham - in London. With UK government guidelines now permitting crowds of 100 per cent for live sport, a capacity crowd of more than 60,000 is expected to attend. Joshua, 31, enters the ring with a professional record of 24 wins and one defeat, with 22 of his victories delivered inside the distance. His sole loss came <a href="https://www.thenationalnews.com/sport/other-sport/anthony-joshua-shocked-by-andy-ruiz-jr-on-historic-night-for-heavyweight-boxing-1.869103" target="_blank">against Ruiz at Madison Square Garden</a> in June 2019 via a seventh round TKO. He immediately avenged that defeat with a unanimous points win over Ruiz in Diriyah. Since then, Joshua claimed a ninth round knockout win over Bulgaria's Kubrat Pulev. Notable wins of Joshua's career include a seventh round TKO against British rival Dillian Whyte, an 11th round TKO against long-time world champion Wladamir Klitschko, a unanimous points win over Joseph Parker in a unified world title fight, and a seventh round TKO of former champion Alexander Povetkin. Usyk will climb through the ropes with a perfect record from 18 professional fights, with 13 coming inside the distance. The 34-year-old Ukrainian operated for much of his career at cruiserweight and became only the fourth fighter in history to hold all four major belts in a division when he became the undisputed champion at 200lbs in 2018. After a successful title defence against Tony Bellew, <a href="https://www.thenationalnews.com/sport/other-sport/watch-oleksandr-usyk-sends-tony-bellew-into-retirement-with-eighth-round-stoppage-1.790307" target="_blank">whom he defeated with an eighth round TKO</a>, Usyk vacated his titles and moved up to heavyweight, where he has fought twice, defeating Chazz Witherspoon via a seventh round retirement and beating Dereck Chisora on a unanimous decision. Both fighters are Olympic champions from the 2012 London Games. Joshua delivered gold in the super-heavyweight division and Usyk won gold in the heavyweight division. As expected, the event boasts a stacked undercard, which begins at 9pm with the WBA Intercontinental middleweight title fight between Christopher Ousley and Khasan Baysangurov. That is followed by Maxim Prodan's welterweight clash with Florian Marku for the IBF International welterweight title at 10pm. Campbell Hatton - the son of former world champion Ricky Hatton - then competes in the fourth fight of his career when he takes on Sonni Martinez at super-featherweight at 10.30pm. Former super-middleweight world champion Callum Smith is up next when he makes his debut at light-heavyweight against Lenin Castillo, scheduled for 11pm, as the Englishman returns to the ring for his first fight since his points defeat to Saul Alvarez in December. The undercard concludes with Laurence Okolie's first defence of his WBO cruiserweight world title when he faces the unbeaten Dilan Prasovic at 12.30am. The event will be streamed live in the UAE on Facebook via the platform's Paid Online Events feature. To watch the fights, head to the <a href="https://www.facebook.com/events/2678420645794629" target="_blank">official Anthony Joshua Vs Oleksandr Usyk event page</a>. The price is Dh36.99.