My Miley

Miley Cyrus’ new boyfriend, Liam Hemsworth, isn’t just another pretty face — dude has a bit of a punch to him.

Just a few months ago — before he and Miley hooked up — 19-year-old Liam (in the gray striped shirt) and his brother (“Star Trek” actor Chris Hemsworth) got into a full-on fistfight with some random dude after an event in Hollywood.

We’re told it all went down after the brothers — who are currently featured in Vanity Fair — engaged in some late-night smack talk with the random guy. The brothers approached the dude — and suddenly a 2-on-1 brawl broke out.

We’re told event security broke up the fight –and managed to separate everyone before cops were needed.

Hope Miley’s into bad boys.