Ukrainian Klitschko and Australian Leapai are set to go head-to-head for the former's WBA, IBF and WBO heavyweight titles in Oberhausen on Saturday.
Australia has never before had a heavyweight title belt holder, and with Leapai preparing to land a big blow in Germany, he and Klitschko were approached publicly by American Briggs, who talked down Leapai and talked up a bout with the champion.
Klitschko's brother Vitali put Briggs into hospital four years ago, although the rash American had no trouble challenging the Ukrainian to a fight - before Leapai put the challenge to Briggs that he was not scared to see him in the ring.
But after the sideshow moved on, it was down to business, and a respectful Klitschko said he was not taking his opponent lightly.
"I'm looking forward to the challenge on Saturday night," he said.
"We can see that Alex Leapai is highly motivated, we saw that already at the first press conference.
"He didn't come here to lose but to win.
"So that means we will see a fight on Saturday that has a lot of action.
"It won't be a fight, were you get bored and fall asleep. This fight will really be very, very exciting."
Klitschko said the fight was more than just defending his belts, but giving people in his homeland hope for the future amid the political unrest in Ukraine.
"Of course, there is a difference between east and west but we are one country, one nation," he said.
"I really hope that this fight will give people the feeling of unity, because the person in the boxing ring is someone that represents the Ukraine.
"And I believe in Nelson Mandela's words, that sports have the power to change the world for the best.
"And this is why this fight is more important than to talk about another one, that I might not be willing to take."
Leapai backed Klitschko's claim that the fight would set out to entertain.
"I'm going to put on the best show," he said.
"I know that Wladimir is going to fight hard to defend his titles but I'm here to win and so is Wladimir so everybody out there who is going to be watching, watch this fight because we're going to make history."