Chamberlain (16-2, 8 KOs) was named as mandatory challenger for Cieslak’s European crown following a dominant points victory over London rival Mikael Lawal for the British and Commonwealth titles at York Hall in October.

The Brixton fighter will make the short trip across South London to Crystal Palace F.C’s Selhurst Park stadium for a second attempt at European glory having previously lost a points decision to Chris Billam-Smith when challenging for the belt in July 2022.

“We relinquished the British title to step up to world level,” Chamberlain said. “I’m grateful that this is a chance to be European champion. This will show that I’m world class and destined to be champion of the world. A win over Cieslak puts me top five in all the governing bodies and on the cusp of a world title fight. To get this opportunity on such a big stadium event makes it even sweeter. I’m sure South London is going to turn out and Selhurst Park will be rocking on June 15th when I’m crowned the new European Champion.”

The 30-year-old will face Pole Cieslak (26-2, 20 KOs), a former two-time world title challenger, who captured the European title with a knockout win over Dylan Bregeon in April 2023 and has since defended the strap with a stoppage victory over former European champion Tommy McCarthy.

Cieslak returns to London following his February 2022 battle with Lawrence Okolie for the WBO world cruiserweight title at the O2 Arena, losing a 12-round decision, and is expected to bring a big Polish fanbase with him to Selhurst Park as he looks to work his way back into world title contention. 

"My goal is to fight for the world championship again, but I am aware that defending my European title, especially against a dangerous and high rated fighter like Isaac Chamberlain brings me closer to that goal,” said the champion. “This is another step for me to reach my dreams. If I want to be world champion, I have to win against rivals like Chamberlain.

"My debut on British soil ended in defeat, so now I will have extra motivation to get even. I'm maturing and making progress with every performance. My last fight ended quicker than I thought it would, so I'm hoping that in the showdown with Chamberlain, I'll have the opportunity to have fun in the ring a little longer."

Promoter Ben Shalom is pleased with how June 15 is taking shape. It’s a busy weekend for boxing, With Subriel Matias vs. Liam Paro in Puerto Rico and the return of Tank Davis, against Frank Martin, in Las Vegas.

“We’re excited to add another huge cruiserweight clash to what’s going to be the must-watch boxing event of the summer,” said Shalom. “It’s a massive moment for Isaac Chamberlain as looks to claim European glory at home in South London against a formidable champion in Michal Cieslak.”

A percentage of every ticket sold will be donated to the Palace For Life Foundation, the official charity of Crystal Palace F.C, which has been working with the community for over 25 years, helping young people grow through the power of sport, inspiring them to find a better path in life and to lead a healthier life.