While Samantha Ronson was at a gig in San Francisco Friday night, Lindsay Lohan drank all her pain away at a party in the Hollywood Hills. It was a late one LiLo…she didn’t even head out with her longtime buddy Patrick Aufdencamp until 2am.

“People were pouring vodka into her red party cup all night,” a guest tells OK!  “She was way beyond incoherent. She was totally smashed and couldn’t even form a sentence. She looked so lonely and lost.” Lindsay stayed at the get-together until just before 3 AM and then moved on to her next pre-dawn party.

Buckle your seat belts kids. It’s going to be a long, bumpy ride until LiLo heads back to rehab.