France’s Takam stepped up as a late replacement for Bulgaria’s Kubrat Pulev, who withdrew last week with a shoulder injury.
But Takam had already been in training for a fight and was on a pre-contract to step in if Pulev did indeed pull out.
Meanwhile, the undercard will feature Kal Yafai’s title defence, Katie Taylor going for global glory and a much-anticipated match-up between heavyweight contenders Dillian Whyte and Robert Helenius.
Express Sport will be ringside to bring you all the action live from the Principality Stadium.
Joshua vs Takam LIVE – latest updates from Cardiff
6.15pm: Really strong start from Buglioni, who twice in the opening two rounds pins Richards to the ropes and lands a couple of solid strikes upstairs.
6.05pm: Next up, it’s the British light-heavyweight title fight which was initially my pick of the undercard until Callum Johnson pulled out. Frank Buglioni has 12 rounds of knockout power and is a thrilling fighter. Big ask for late replacement 10-0 super-middleweight Craig Richards to take the title off him.
5.50pm: Buatsi wins with a late knockdown and an improved performance. Sall was tough though. A good learning fight.
“I got six rounds in the bank,” Buatsi says.
“Credit to my opponent because he knew what he was doing.”
5.30pm: Rio 2016 bronze medallist Joshua Buatsi is into the ring and has started well against Saidou Sall. One left uppercut from Buatsi rocks Sall but he looks to have a decent chin. Still, expect nothing but a third professional win for the 24-year-old here.
5.15pm: Okolie approaching the halfway point of his clash with Adam Williams, scheduled for six rounds. The former Team GB righter certainly looks as though he has plenty left to give but Williams is knocked down in the third round after plenty of punishment and the towel goes in from his corner.
Another convincing win for Okolie, who improves to 6-0.
5pm: The doors are open. The roof is shut. 78,000 tickets have been sold and all we need now are some boxers. There is a packed undercard with a lot of quality British fighters on show before the best of them all, Anthony Joshua, takes to the ring for the first time since beating Wladimir Klitschko at around 10.15pm.
First up will be big-hitting cruiserweight Lawrence Okolie in his sixth fight as a professional, defending his unbeaten record. He’ll be along in a few minutes.