Michaels, star of the reality show "Rock of Love," took to the stage with his hair-metal band Poison during the telecast's opening production number, featuring performances from the season's Broadway musicals.
They performed "Nothin' But a Good Time" with the cast of "Rock of Ages," and as Michaels exited the stage, a descending set piece smacked him on the head and knocked him to the ground.
Tonys spokeswoman Christina Stejskal says the rocker "missed his mark." Though it looked it, he did not break his nose. Stejskal did not immediately know the extent of his injury.
"Rock of Ages" celebrates 1980s hair music and features songs by Journey and other bands. It stars Constantine Maroulis as an aspiring rock star.