IT'S now two years since CM Punk last stepped into the octagon - but the WWE star is back for more.
The 39-year-old was given a brutal welcome at UFC 203, where Mickey Gall dispatched him in just 154 seconds.
But he'll be hoping for better this time out as he steps back into the firing line against Mike Jackson.
Current middleweight champ Robert Whittaker and former interim title challenger Yoel Romero serve as the main event - but the fight is now a non-title catchweight bout after Romero failed to make weight at Friday's weigh-in.
How can I live stream or watch on TV?
YOU can catch all the action live on BT Sport, which holds exclusive rights to the UFC in the UK and Ireland.
To stream, download the BT Sport App and watch on the move through your mobile, tablet or laptop.
Here on SunSport we will be bringing you a LIVE BLOG from Chicago, which will bring you the main undercard bouts and headliners.
When is UFC 225?
THIS bumper night takes place on Saturday, June 9 - or the early hours of Sunday here in the UK.
Get the coffee in because it will be an early one, with the undercard kicking off around 12am BST.
What time is CM Punk due to fight?
PUNK is on the main card, which starts at 3am BST.
He is set to be the first fight on the main card, meaning he will be on shortly after 3am.
The prelims started at 1am.
Who is on the card?
THERE'S a packed card at the United Center - here's who will be appearing at UFC 225.
- Robert Whittaker vs. Yoel Romero (Romero failed to make weight so fight is now non-title catchweight bout)
- Rafael dos Anjos vs. Colby Covington (WELTERWEIGHT TITLE FIGHT)
- Holly Holm vs. Megan Anderson
- Andrei Arlovski vs Tai Tuivasa
- CM Punk vs. Mike Jackson
- PRELIMINARY CARD
- Alistair Overeem vs. Curtis Blaydes
- Claudia Gadelha vs. Carla Esparza
- Ricardo Lamas vs. Mirsad Bektic
- Chris de la Rocha vs Rashad Coulter
- Rashad Evans vs. Anthony Smith
- Joseph Benavidez vs. Sergio Pettis
- Clay Guida vs. Charles Oliveira
- Dan Ige vs Mike Santiago