WBA world featherweight champion Carl Frampton will face the deposed Leo Santa Cruz in a rematch in Las Vegas on January 28.
Frampton stepped up a division after unifying the IBF and WBA super-bantamweight titles with an impressive victory over Scott Quigg last February.
The Northern Irishman took on the previously undefeated Santa Cruz in New York in July, winning via a majority points decision in another strong showing.
A date for Frampton's first defence has now been set, with a rematch against the dethroned Mexican at the MGM Grand.
"This is one of the biggest fights in world boxing. Our first fight in July was a war and I believe that January 28th will be exactly the same," said Frampton in a statement.
"It's a dream come true for me to be headlining in Las Vegas, where some of the biggest fights of all time have taken place.
"I've learnt a lot from our first fight, Leo is a warrior but I'm going to win even more convincingly the second time around."