Anthony Joshua will not be afforded much rest after recapturing the world heavyweight titles by beating Andy Ruiz – as the WBO have ordered him to fight mandatory challenger Oleksandr Usyk within 180 days.

The mercurial Ukrainian has successfully stepped up since cleaning up at cruiserweight, beating Chazz Witherspoon in October.

And WBO rules state that their champions are automatically elevated to mandatory challengers once they move up in weight, meaning AJ must now defend his titles against Usyk before next summer.

WBO President Paco Valcarcel stated: “Clash of the Dunes is over... Now clash of mandatories will be next. WBO mandatory challenger Usyk within 180 days.”

That means Joshua vs Usyk must take place before June 4 next year, putting the Briton in a tricky situation immediately after becoming a two-time champion.

Anthony Joshua vs Andy Ruiz Jr II in pictures Show all 65 1 /65 Anthony Joshua vs Andy Ruiz Jr II in pictures Anthony Joshua vs Andy Ruiz Jr II in pictures Anthony Joshua vs Andy Ruiz The Diriyah Arena hosts the rematch between Andy Ruiz and Anthony Joshua in Saudi Arabia. Action Images via Reuters Anthony Joshua vs Andy Ruiz Jr II in pictures Anthony Joshua vs Andy Ruiz The purpose-built 15,000-capacity arena was erected for the bout in fewer than six weeks. Getty Images Anthony Joshua vs Andy Ruiz Jr II in pictures Anthony Joshua vs Andy Ruiz UFC champion Khabib Nurmagomedov arrives at the Dirayah Arena. Action Images via Reuters Anthony Joshua vs Andy Ruiz Jr II in pictures Anthony Joshua vs Andy Ruiz Saul 'Canelo' Alvarez arrives at the Diriyah Arena. PA Anthony Joshua vs Andy Ruiz Jr II in pictures Anthony Joshua vs Andy Ruiz Fans attemped to remain dry as rain struck the arena early on. Reuters Anthony Joshua vs Andy Ruiz Jr II in pictures Anthony Joshua vs Andy Ruiz There were fears the undercard could be cut short due to rain but defiant fans remained in their seats for the bouts. Action Images via Reuters Anthony Joshua vs Andy Ruiz Jr II in pictures Anthony Joshua vs Andy Ruiz Umbrellas and ponchos were a familiar sight across the crowd. Action Images via Reuters Anthony Joshua vs Andy Ruiz Jr II in pictures Anthony Joshua vs Andy Ruiz But they did not let the weather dampen their spirits on the night. Action Images via Reuters Anthony Joshua vs Andy Ruiz Jr II in pictures Anthony Joshua vs Andy Ruiz A sparse crowd watched on as the undercard got underway. Getty Images Anthony Joshua vs Andy Ruiz Jr II in pictures Anthony Joshua vs Andy Ruiz Fans smile in the rain ahead of the opening bout. PA Anthony Joshua vs Andy Ruiz Jr II in pictures Zuhayr Al Qahtani vs Omar Dusary Zuhayr Al Qahtani kicked off the bill in an eight-round bout for the WBC Middle East Lightweight Championship against Omar Dusary. Getty Images Anthony Joshua vs Andy Ruiz Jr II in pictures Zuhayr Al Qahtani vs Omar Dusary Al Qahtani (right) attempts to land a right hand on Dusary. Getty Images Anthony Joshua vs Andy Ruiz Jr II in pictures Zuhayr Al Qahtani vs Omar Dusary Al Qahtani looked the more livelier boxer early on. Getty Images Anthony Joshua vs Andy Ruiz Jr II in pictures Zuhayr Al Qahtani vs Omar Dusary Al Qahtani and Dusary tumble to the canvas after losing their footing. Getty Images Anthony Joshua vs Andy Ruiz Jr II in pictures Zuhayr Al Qahtani vs Omar Dusary Al Qahtani celebrates his victory by unanimous points decision. Getty Images Anthony Joshua vs Andy Ruiz Jr II in pictures Anthony Joshua vs Andy Ruiz Fears that females would not be allowed to attend were immediately dismissed. Getty Images Anthony Joshua vs Andy Ruiz Jr II in pictures Hopey Price vs Swedi Mohamed Hopey Price celebrates beating Swedi Mohamed. PA Anthony Joshua vs Andy Ruiz Jr II in pictures Flip Hrgovic vs Eric Molina Flip Hrgovic celebrates beating Eric Molina. Getty Images Anthony Joshua vs Andy Ruiz Jr II in pictures Mahammadrasul Majidov vs Tom Little The referee stops Tom Little in the second round to hand victory to Majid. PA Anthony Joshua vs Andy Ruiz Jr II in pictures Mahammadrasul Majidov vs Tom Little Majid celebrates his stoppage win. Getty Images Anthony Joshua vs Andy Ruiz Jr II in pictures Dillian Whyte vs Mariusz Wach Dillian Whyte defeated Mariusz Wach. Getty Images Anthony Joshua vs Andy Ruiz Jr II in pictures Alexander Povetkin vs Michael Hunter Michael Hunter arrived in the ring in full Predator attire ahead of his bout with Alexander Povetkin. PA Anthony Joshua vs Andy Ruiz Jr II in pictures Alexander Povetkin vs Michael Hunter The pair dished up a thrilling 12-round heavyweight slog. Getty Images Anthony Joshua vs Andy Ruiz Jr II in pictures Alexander Povetkin vs Michael Hunter Both Povetkin and Hunter hit the canvas without taking counts as the fight went the distance. Getty Images Anthony Joshua vs Andy Ruiz Jr II in pictures Alexander Povetkin vs Michael Hunter The judges scored the contest a split draw. Getty Images Anthony Joshua vs Andy Ruiz Jr II in pictures Anthony Joshua vs Andy Ruiz Promoter Eddie Hearn makes his way into the ring ahead of the main event. PA Anthony Joshua vs Andy Ruiz Jr II in pictures Anthony Joshua vs Andy Ruiz Announcer Michael Buffer prepares to welcome Joshua and Ruiz to the ring for the main event. Getty Images Anthony Joshua vs Andy Ruiz Jr II in pictures Anthony Joshua vs Andy Ruiz Michael Buffer introduces the challenger Anthony Joshua. Getty Images Anthony Joshua vs Andy Ruiz Jr II in pictures Anthony Joshua vs Andy Ruiz Joshua looked nervous as he made his way to the ring. Getty Images Anthony Joshua vs Andy Ruiz Jr II in pictures Anthony Joshua vs Andy Ruiz Joshua points to the sky as his name is read out. Getty Images Anthony Joshua vs Andy Ruiz Jr II in pictures Anthony Joshua vs Andy Ruiz The magnitude of the night looked crystal clear on Joshua's face. PA Anthony Joshua vs Andy Ruiz Jr II in pictures Anthony Joshua vs Andy Ruiz Champion Andy Ruiz makes his way to the ring with the WBA, IBO and WBO PA Anthony Joshua vs Andy Ruiz Jr II in pictures Anthony Joshua vs Andy Ruiz Ruiz stares down Joshua across the ring. PA Anthony Joshua vs Andy Ruiz Jr II in pictures Anthony Joshua vs Andy Ruiz Ruiz immediately looked to take the centre of the ring and walk down Joshua. Getty Images Anthony Joshua vs Andy Ruiz Jr II in pictures Anthony Joshua vs Andy Ruiz Whereas Joshua looked to keep distance between himself and Ruiz. PA Anthony Joshua vs Andy Ruiz Jr II in pictures Anthony Joshua vs Andy Ruiz Joshua landed a big right hand to cut Ruiz above his left eye in the first round. Action Images via Reuters Anthony Joshua vs Andy Ruiz Jr II in pictures Anthony Joshua vs Andy Ruiz Ruiz brushed off the cut and got back to business quickly. Action Images via Reuters Anthony Joshua vs Andy Ruiz Jr II in pictures Anthony Joshua vs Andy Ruiz Ruiz did have blood flowing down his face early on. Action Images via Reuters Anthony Joshua vs Andy Ruiz Jr II in pictures Anthony Joshua vs Andy Ruiz Ruiz's face shows the damage of the opening round. Getty Images Anthony Joshua vs Andy Ruiz Jr II in pictures Anthony Joshua vs Andy Ruiz But Joshua suffered a cut in round two after a clash of heads. Getty Images Anthony Joshua vs Andy Ruiz Jr II in pictures Anthony Joshua vs Andy Ruiz The two began to trade as the fight wore on. Getty Images Anthony Joshua vs Andy Ruiz Jr II in pictures Anthony Joshua vs Andy Ruiz But Joshua was able to keep Ruiz at his range and dominate the fight. Getty Images Anthony Joshua vs Andy Ruiz Jr II in pictures Anthony Joshua vs Andy Ruiz Ruiz at times managed to work inside and give Joshua something to think about. Action Images via Reuters Anthony Joshua vs Andy Ruiz Jr II in pictures Anthony Joshua vs Andy Ruiz Ruiz shaded the eighth as he got Joshua flush. Getty Images Anthony Joshua vs Andy Ruiz Jr II in pictures Anthony Joshua vs Andy Ruiz But the ninth proved a scrappy round as the two started to become edgy. Action Images via Reuters Anthony Joshua vs Andy Ruiz Jr II in pictures Anthony Joshua vs Andy Ruiz The two needed splitting apart on one occasion. Getty Images Anthony Joshua vs Andy Ruiz Jr II in pictures Anthony Joshua vs Andy Ruiz The referee had to give Joshua a ticking off when he refused to acknowledge him. Action Images via Reuters Anthony Joshua vs Andy Ruiz Jr II in pictures Anthony Joshua vs Andy Ruiz But the battle quickly resumed. PA Anthony Joshua vs Andy Ruiz Jr II in pictures Anthony Joshua vs Andy Ruiz Joshua was able to re-establish his dominance. Getty Images Anthony Joshua vs Andy Ruiz Jr II in pictures Anthony Joshua vs Andy Ruiz And in the 11th Joshua caught Ruiz with a powerful straight right that put the defending champion in reverse. Action Images via Reuters Anthony Joshua vs Andy Ruiz Jr II in pictures Anthony Joshua vs Andy Ruiz The strong round meant that Ruiz needed a knockout to retain the belts, but it never came. Action Images via Reuters Anthony Joshua vs Andy Ruiz Jr II in pictures Anthony Joshua vs Andy Ruiz Joshua celebrates at the end of the bout while Ruiz is tended to. Action Images via Reuters Anthony Joshua vs Andy Ruiz Jr II in pictures Anthony Joshua vs Andy Ruiz Announced as a two-time champion, Joshua reclaims the titles. Action Images via Reuters Anthony Joshua vs Andy Ruiz Jr II in pictures Anthony Joshua vs Andy Ruiz And while he opened the door to a third match against Ruiz, he insisted there is no decision on where his future lies. Action Images via Reuters Anthony Joshua vs Andy Ruiz Jr II in pictures Anthony Joshua vs Andy Ruiz Joshua decided to praise his opponent and say he would be happy to do it a third time. Action Images via Reuters Anthony Joshua vs Andy Ruiz Jr II in pictures Anthony Joshua vs Andy Ruiz While Ruiz admitted that he got his preparation wrong and put on too much weight. Action Images via Reuters Anthony Joshua vs Andy Ruiz Jr II in pictures Anthony Joshua vs Andy Ruiz Ruiz accepted that he was sluggish that played into Joshua's hands. AFP via Getty Images Anthony Joshua vs Andy Ruiz Jr II in pictures Anthony Joshua vs Andy Ruiz Promoter Eddie Hearn celebrates with Joshua after the victory is announced. PA Anthony Joshua vs Andy Ruiz Jr II in pictures Anthony Joshua vs Andy Ruiz Joshua grins with the titles back in his corner. Getty Images Anthony Joshua vs Andy Ruiz Jr II in pictures Anthony Joshua vs Andy Ruiz And he was quick to put the straps back around him and show off his gold. Getty Images Anthony Joshua vs Andy Ruiz Jr II in pictures Anthony Joshua vs Andy Ruiz Ruiz could only watch on after the losing the titles. Action Images via Reuters Anthony Joshua vs Andy Ruiz Jr II in pictures Anthony Joshua vs Andy Ruiz With Joshua now a two-time world champion. Action Images via Reuters Anthony Joshua vs Andy Ruiz Jr II in pictures Anthony Joshua vs Andy Ruiz Joshua's large entourage joined him in the ring to celebrate. Getty Images Anthony Joshua vs Andy Ruiz Jr II in pictures Anthony Joshua vs Andy Ruiz But Joshua made sure he took a moment to celebrate with his father too. Getty Images Anthony Joshua vs Andy Ruiz Jr II in pictures Anthony Joshua vs Andy Ruiz By the end of the night, Joshua was back on top of the world. Getty

The queue of potential opponents will grow by the day, too, with the IBF mandatory also due soon.

Kubrat Pulev has been biding his time for a shot at Joshua.

With Deontay Wilder, who holds the WBC belt, and Tyson Fury set to fight each other next February, and likely for a third time later in the year, Joshua will be forced to carve out his own route.

Joshua celebrates with his titles after beating Ruiz (Action)

Ruiz called for a third fight, but Joshua played that down, perhaps aware of his precarious mandatory situation.

“I don’t know, I don’t want to talk too much. A big mouth is not what people respect. Whatever we can do, I will do,” Joshua told BBC 5 Live.