Anthony Joshua could face rival world heavyweight champion Tyson Fury in a huge domestic showdown later this year, says promoter Eddie Hearn.
Joshua knocked out Charles Martin in two rounds to claim the IBF crown with his 16th straight knockout win on Saturday at The O2.
WBO and WBA champion Fury, who dethroned Wladimir Klitschko in November, and former title holder David Haye were immediately touted as Joshua's possible opponents for his first title defence.
However, Hearn says Fury is the priority and Haye, who will return to the ring for the second fight of his comeback at The O2 on May 21, can wait.
"I think that's unrealistic, as much as Haye wants the fight, he knows it's a proper fight and that fight is going to build and grow," Hearn told Sky Sports News HQ.
"Tyson Fury is our pick before that because he has got the belts, the other two belts, and I think a unification fight has to be a priority.
"Haye against Joshua is a massive fight, probably realistically next spring or summer but Fury could be one for 2016."
Hearn revealed he has already spoken to Fury's trainer and uncle about the pair meeting.
"I've chatted to Peter Fury about it, we know how big the fight is and both guys, both camps, really fancy their chances in the fight. So I think that's a fight you will see sooner rather than later.
"We're going to go in June or July, then Klitschko-Fury is on July 9 and if Tyson wins that fight he will be looking to go November time and so will we.
"Britain has two world champions who I know for a fact will step in the ring with each other and put all the belts on the line. Now when was the last time we had a British world heavyweight champion before these two?
"Now we've got two and a chance for a unification fight that I think will never ever happen again in British boxing.
"It's great times and may they both keep on winning for as long as possible because one day they will meet and that will be an event. I know we always say the biggest event of all time and we've had a few lately but that will blow the socks off."