Rita Ora's Birthday Collision with Lewis Hamilton ... and a Pole!

Rita Ora's 25th birthday was almost a night she'd never remember because she almost knocked herself out by smashing into a giant metal pole.

Ora was leaving a London restaurant Tuesday night after celebrating her bday with friends, including Formula One stud Lewis Hamilton. Looks like it was a verrry good night ... based on Rita's near headfirst stumble, anyway.

Friends don't let friends concuss alone.