Firefighters had to extricate four people from beneath the vehicle, including a boy, after the 12:30 p.m. crash at the Egg & I restaurant on Sahara Avenue, several blocks west of the Las Vegas Strip, witnesses said.
The injured were taken to two hospitals, and some were hurt seriously, said Las Vegas fire spokesman Tim Szymanski.
Suziliene McDonald said she was sitting with two sisters in the restaurant when she saw the vehicle speed toward the window.
"I screamed, 'A car's coming!' and it exploded through the window," McDonald said. "The motor was still revving and the dust came right after it, just like in the movies."
Two men inside the Lexus sedan sat for a moment and then tried to run, McDonald said. Several men jumped over a short wrought-iron fence and caught them to hold them until police arrived.
"He kept saying he blacked out," McDonald said of the driver, who sat shirtless in handcuffs on the sidewalk while police investigated. "But he was awake when he ran from the car."
Police said the driver would probably face felony reckless driving charges.
A passenger in the vehicle sat later on a curb in a blue T-shirt, dark trousers and sneakers and refused to speak with reporters. Police said he was not charged with a crime.
McDonald, an executive with a nonprofit trauma and counseling agency in Las Vegas, said she began assessing people's injuries before paramedics and police arrived. Two girls appeared to have been cut by flying glass, she said. One woman with a broken leg asked where her purse was.
McDonald said the car balanced on a patio chair over a woman who lay on her stomach, bleeding, with the car and a chair atop her. The woman's son was stuck in a crouching position beneath the car near her.
Manager Sarah Gehringer said the restaurant may have had 150 people inside and on the patio before the crash.
One of the injured was a restaurant employee who was standing near the window when the car burst through. Gehringer said he was knocked into the kitchen by the force of the crash and was hospitalized.
Police said the Lexus was heading westbound on the busy thoroughfare when it hit at least two other vehicles before veering across a median toward the restaurant.
A half-moon set of skid marks crossed three travel lanes and two turn lanes leading toward the picture windows of the restaurant set at the end of a strip mall complex.