After retiring from professional wrestling in 2014, Punk pursued a career in mixed martial arts and was signed by the UFC in December of that year.
His first professional fight took place on September 10, 2016, at UFC 203 against Mickey Gall, where he lost via submission in the first round.
The scuffle reportedly stemmed from an ROH show in which Hart performed three unplanned spots putting several other wrestlers in danger of injury.
On September 26, in his OVW television debut, Punk suffered a ruptured eardrum and broken nose after Danny Inferno hit him with an overly stiff right hand.
Despite the injury, Punk finished the match and quickly recovered.
In WWE, he was also a one-time World Tag Team Champion (with Kofi Kingston), and one-time Intercontinental Champion, making him the 19th WWE Triple Crown Champion and the fastest man in WWE history to achieve this feat, doing so in 203 days.
In addition, he was the 2011 WWE Superstar of the Year and the first two-time Money in the Bank winner.
Though he had accepted the deal, Punk defeated Austin Aries to win the ROH World Championship on June 18 at Death Before Dishonor III.