Ryan Lochte was on the verge of being attacked Monday night during the live season premiere of “Dancing with the Stars” … and the man who rushed the staged was taken down by security and detained.

Lochte had just finished a foxtrot with Cheryl Burke and they were standing next to Tom Bergeron to get the judges’ feedback, when a group in the audience ripped their shirts open to reveal the round symbol for “No Lochte” on their t-shirts. The group was booing the swimmer when one rushed the stage.

The cameras did not capture the incident, but viewers on the East Coast could hear the commotion.

We don’t know if the guy in question was arrested.