Beyonce and Jay-Z
Jay-Z and Beyonce: The power couple perform during their On The Run tour AFP / Getty Images

A drunken concert-goer is in police custody after biting off more than he could chew during Beyoncé and Jay Z's On the Run tour.

Roberto Alcaraz-Garnica, 25, of San Diego was arrested inside the Rose Bowl in Pasadena, California following a violent altercation with another fan.

He was charged with sexual battery and causing mayhem for allegedly biting off the tip of another man's finger after groping the victims' girlfriend.

"The suspect sexually assaulted the female victim," said Pasadena police Lt. John Luna. "The woman's boyfriend confronted the alleged groper, and a fight ensued.

"During the altercation, the suspect bit the victim, causing serious injury to his finger," the police said. "He lost the tip of one of his fingers."

Almost 55,000 fans attended the concert where the attack took place.

Suspect Alcaraz-Garnica is being held in lieu of $100,000 bail. He scheduled to appear in court at a later date.

Neither Beyoncé nor Jay Z, who will hit the stage again this weekend, has commented on the finger biting incident.