During the pep rally, Rivera approaches, then turns around and dances in sync with the music and the performers.
Rivera's appearance was a surprise to all except the Cardinal Gibbons dance coach, WPTV reported. Rivera, from Puerto Rico, practiced the initial moves in the week leading up to the pep rally, Fox News reported. Then he memorized the entire routine.
Predictably, Rivera's moves drew a raucous response from the student body.
Rivera was not giving interviews about his performance, the Herald reported. However, social media posters had plenty to say.
"Now this is what I'd like to refer to as dancing for Jesus!" Twitter user Laurie Harris tweeted. "Love it!"
Rivera now has his own hashtag: #dancingpriest.