Who knew Lindsay Lohan and Scarlett Johansson, two starlets who share bra sizes (occasionally) and ingenue roles, secretly nurse a nasty feud?

The rift was exposed after it was reported that Lohan scrawled, "Scarlett is a bloody [unladylike word here]" on the wall of a New York bar bathroom Tuesday night.

Johansson should be flattered. You're no one in Hollywood unless you're battling someone else, and as David Letterman and Paris Hilton know, a little rivalry is good for business. Let's rumble!

Lindsay Lohan vs. Scarlett Johansson

The matchup: Lohan, a 19-year-old former devotee of "extreme dieting" and Johansson, a 21-year-old top-heavy actress with a penchant for bright red lipstick.

What happened: Diet Coke lovers Lindsay and Kate Moss' latest drunken bender resulted in mild supermodel-on-teen star pole action and Lohan scrawling profane things about Scarlett, adding "peace and love, f——r" in a Darkroom bar bathroom.

The cause: Maybe it's because Scarlett gets all the critically-acclaimed roles, like "Match Point" and "Lost in Translation," and Lindsay's last movie was about a talking car. Or, Lohan's still sour that she's bedding Jared Leto, Scarlett's ex.

Our pick: Lindsay could be the wild card here; she's a tough girl from Long Island who probably isn't afraid to fight dirty. And scratch. And pull hair. And her dad knows people.