Khloe Kardashian -- Ambushed by Lamar at SoulCycle (PHOTO)

Khloe Kardashian was blindsided at 6:45 AM Wednesday by soon-to-be ex-husband Lamar Odom, who launched a verbal attack.

Khloe was on her way into SoulCycle in Beverly Hills when Lamar came out of nowhere, screaming at her. An eyewitness tells us Lamar was demanding that she talk to him. She kept walking as he was screaming. At that point Lamar touched Khloe's arm and she screamed at him, "Get off of me, get off of me. Stop. Stop."

Another eyewitness asked Khloe if she wanted them to call the cops, and Lamar screamed, "You're not going to call the cops on Lamar Odom."

Khloe then screamed, "How did you know I was here?" He didn't give a clear answer.

We're told Khloe was visibly freaked out and bolted to her car and drove away.

TMZ broke the story, Khloe and Lamar signed divorce docs last month, after the divorce lay dormant for more than a year.