zaclillycollinssidebyside.jpg

Looks like Zac Efron has a new girl! The 24-year-old hunk took new "it" girl Lily Collins on a date Saturday night at LA's STK steakhouse.

We spotted the two trying to slip out the back door and while we just barely caught Zac slipping into a chauffeured SUV, we got a surprised-looking Lily as she made her way to the same car.

Collins, who turns 23 next month, will appear in her biggest role to date as Snow White in the upcoming Mirror Mirror, while Zac has three big films coming out this year -- The Paperboy, The Lucky One and another yet-untitled movie.

The pair were trying to avoid attention, according to our photographers at the restaurant last night: "Zac literally ran to the car and jumped in, leaving Lily behind. But Lily kept her cool and took her time. She wasn't as worried about not being seen by us. She took her time. She probably didn't want to trip in her heels!"

Collins was recently linked to Taylor Lautner who, according to reports, is back together with his high school sweetheart. Zac was rumored to be dating Taylor Swift just a few weeks ago, but most sources shot down those rumors as false.

Maybe Lily is Zac's REAL girlfriend ... seems like a relationship he wants to protect!