Rachel Zoe's Los Angeles Home Broken Into

Rachel Zoe's glam weekend in Las Vegas took a dark turn back home ... 'cause TMZ has learned her Los Angeles house was broken into.

Law enforcement sources tell TMZ ... "The Real Housewives of Beverly Hills" star's Bel Air property was burglarized early Sunday morning while she was in Sin City for the opening of Zero Bond Las Vegas.

We're told Zoe's alarm company received an activation alert and the alarm company quickly notified police. Patrol units in the neighborhood responded and spotted two male suspects leaving the property. We're told one of those suspects is in custody.

Our sources say no one was home during the break-in. It's still unclear what -- if anything -- was taken.

We broke the story ... Zoe's "RHOBH" costars Kathy Hilton and Sutton Stracke were both burglarized last November while they were in Las Vegas for BravoCon. In fact, Kathy's home is just a short walk from Rachel's.