Miley Cyrus -- Front Row for 82-Year-Old Stripper!!

Moments before Miley Cyrus' alleged woman-punches-man altercation ... something way more traumatic happened -- a seriously close encounter with an 82-year-old stripper!

The T&A nightmare went down Saturday night at the Beacher's Madhouse theater in Hollywood, where Miley was standing front row when the octogenarian ass-shaker hit the stage ... gently, of course.

The well-preserved dancer -- billed as the world's oldest female stripper -- worked the crowd, including Miley, into a frenzy.

As TMZ first reported, Miley was named a suspect in a criminal battery after an alleged scrap that night ... between Miley, her fiance Liam Hemsworth and another guy in the theater.

Miley denies hitting anyone, and several witnesses say the same.