New move: Pro wrestling star CM Punk making debut in UFC 203

One show, one match at a time, CM Punk climbed to the top of pro wrestling, acquiring unimagined fame and fortune along the way.

It wasn't enough. He needed more, a challenge to satisfy his inner drive. A dream.

"And now," he said, "here I am."

On the verge of stepping into the UFC's octagon, an arena where some say he doesn't belong.

One of WWE's biggest stars before leaving the squared circle two years ago, Punk makes his long-awaited debut as an MMA fighter on Saturday night in UFC 203, where he won't be in the main event but where he's the top draw and greatest curiosity.

When he takes center stage a month shy of his 38th...