Crolla will be looking to become a two-time world champion in the division but faces a task of some magnitude when he takes on The Independent's pound-for-pound king in Lomachenko, with the Ukrainian a consecutive Olympic gold medal-winning amateur in 2008 and 2012.
Manchester-born Crolla won the WBA belt in his home city when he knocked out Darleys Perez in 2015 but lost it less than a year later when Jorge Linares came to town and put on a classy performance.
Linares later lost his strap to Lomachenko.
Here's everything you need to know about the big one coming up in LA.
When and where is the fight?
The fight between Lomachenko and Crolla takes place at the Staples Centre in Los Angeles tonight.
What time will the ring walks be?
Expected to be around 4.30am, so if you're watching it in the UK you better be prepared to stay up.
What TV channel will it be on?
Sky Sports! You won't have to pay for this one if you're a subscriber to Sky Sports but you will have to stay up late.
Are tickets still available?
Yes indeedy. From $50-$300 you can find them right here.
What's at stake and what are their records?
For Crolla, not a lot. If he wins then he'll be seen as a great in British boxing and known across the world as the man who dethroned the pound-for-pound king. He'll also get the WBA (Super), WBO and The Ring lightweight belts for his troubles. His professional record is 43 fights, 34 wins, six losses and three draws. He comes in as the much more experienced man in the pro game.
Lomachenko, however, boasts an amateur record of 396 wins to one defeat, and since coming into the pro ranks won a world title in his third fight, a two-weight champion in his seventh and a three-weight world champion in his twelfth. He has lost just once, in his second fight against Orlando Salido and has since gone on to dismantle each of his opponents, boasting a 12-1 record.
What is the full fight schedule?
Gilberto Ramirez vs Tommy Karpency
Arnold Barboza Jr vs Mike Alvarado
Alexander Besputin vs Alfredo Blanco
Janibek Alimkhanuly vs Cristian Olivas
Vijender Singh vs Calvin Metcalf
Guido Vianello vs Lawrence Gabriel
Chris Zavala vs Sergio Gonzales
Elvis Rodriguez vs Kevin Luna
Lomachenko will stop Crolla, who has a lot of heart but ultimately is out of his depth at this level.
Lomachenko to win: 1/100
Crolla to win: 18/1