Chicago hosts its first UFC pay-per-view event Saturday at the United Center, and all eyes will be on two-time former WWE champion and Chicago native CM Punk.

Punk, whose real name is Phil Brooks,  will enter the cage breathing a sigh of relief after being cleared Tuesday in a defamation lawsuit filed against him by a WWE doctor.

“I do have a sense of relief because I wasn’t in court today,” said Punk, who faces  Mike Jackson in a welterweight fight on the UFC 225 main card. “That’s a start.”

Dr. Chris Amann sued Punk and another wrestler, Colt Cabana (real name Scott Colton), seeking nearly $4 million after what Amann claims were damaging comments made by the pair in a November 2014 podcast hosted by Cabana. Punk said he felt a sense of relief when he shared his story on the podcast about WWE doctors failing to diagnose a lump that turned out to be a staph infection.

“And look what happened,” he said.

Now, nearly 4½ years after his last WWE match, he’s focused on getting both feet out of the wrestling world and planted in mixed martial arts.

He made his Octagon debut against Mickey Gall at UFC 203 in 2016 — a fight the UFC community characterized as a complete disaster after Punk lost by submission in the first round.

Punk doesn’t entirely disagree.

“I would describe it as disappointing,” he said. “I mean, I lost, and there’s no fun in that. I don’t have a super-positive story for you. But my perspective was, I took the ‘L’ — now where do we go from here?”

While many saw the loss as a clear indication that Punk wasn’t ready for the UFC, he said it gave him a solid foundation to build upon and forced him to examine his weaknesses in the cage.

“What do I have to work on?” Punk asked himself.

The answer, he said, was everything.

He and Jackson have an interesting common thread. Like Punk, Jackson also lost to Gall by submission in the first round of his UFC debut.

Both will step into the cage Saturday with something to prove. One possible advantage for Punk: He’ll be competing in front of his home crowd.

“It’s everything to me,” Punk said. “I think for sure I feel the pressure, but it’s a good pressure. It’s kind of a back-against-the-wall mentality, but I’m in my backyard. I can draw from that and gain strength from that.”

Lightweight Clay Guida and heavyweight Curtis Blaydes also get the home-crowd factor. Guida (34-14) faces Charles Oliveira, and Blaydes (9-1) will meet Alistair Overeem.

The only previous UFC pay-per-view in the area was UFC 90 in 2008 at Allstate Arena in Rosemont.