FORMER WWE superstar CM Punk promised to be back in the cage despite losing at his mixed martial arts debut Sunday, reported ESPN.

Punk, 37, whose real name is Phil Brooks, lost to fellow American fighter, Mickey Gall, 24 in a much-anticipated welterweight fight at UFC 203.

”In life, you go big or you go home. I just like to take challenges. This was a hell of a mountain to try and climb.

“I didn't get to the summit today, but that doesn't mean I'm going to give up. It doesn't mean I'm going to stop,” he told a post-fight interview.

Punk was taken down in just seconds after the start of the fight, where Gall quickly moved to full mount — raining powerful strikes to the side of Punk’s head.

Gall then saw an opening for him to apply the rear naked choke, forcing Punk to tap out after the second minute of round one.

Punk (pic) admitted that his defeat leaves his career in the UFC in doubt. - AP photo

Punk, who is also the husband of former WWE Diva A.J Lee, left the WWE in 2015 to sign with the Ultimate Fighting Championship (UFC) for a multiple fight contract.

However, Punk’s loss against Gall has left his UFC future in doubt as he himself is now unsure of his new career path.

“I don’t know what happens from here,” he was quoted as saying on Daily Mail.

According to a report on Forbes, even UFC President Dana White suggested for Punk to fight in smaller MMA promotions rather than the UFC.

White said if Punk’s ambition was to return to the cage, it wouldn’t be at the highest level.

Still, his debut at the UFC has earned him the admiration and respect from many fighters and fans.

The only pro wrestler besides Punk who made the transition from the WWE to the UFC, was Brock Lesnar.