Official: Anthony Joshua, Joseph Parker, to meet in unification bout on March 31

In a battle of heavyweight gladiators, two-belt titleholder Anthony Joshua and one-belt titlist Joseph Parker are officially set to fight on March 31 at Principality Stadium in Cardiff, Wales, where Joshua drew a sold-out crowd of 78,000 for his last fight in October.

The deal was in the works for the last couple of months and was nearly a done deal as of Dec. 28.

"These fights aren't easy because there is a lot on the line, so respect to Team Parker for taking the challenge," Joshua said via ESPN. "And you know me; I love this game. I am looking forward to it. Training camp is underway, and before you know it, March 31 will be upon us."

Parker (24-0, 18 KO's), 26, of New Zealand, won a vacant title by majority decision over Andy Ruiz Jr. in December 2016 in his backyard, and has made two defenses. He told SkySports after arriving in Britain Sunday that he is ready to inflict "a lot of damage" on Joshua.

"I can do a lot of damage. I feel like it's my time," Parker said. "He thinks it's his time, so it's just about who trains hardest, who wants it more, and we're both going to pour our undefeated records on the line.

"May the best champion win."

The unbeaten Joshua, 28, has knocked out all 20 of his previous opponents, including an 11th-round knockout of Wladimir Klitschko in April. The all-time classic bout, which saw both fighters hit the deck, earned FightNights.com's 2017 Fight of the Year award.

Although it's not official, the bout is expected to air on Showtime.