Two patrons enjoying their morning at an outdoor table of the Cupcake Room on Norton Street in Leichhardt found themselves in a terrifying situation around 9:50 a.m. when a silver BMW unexpectedly crossed two lanes of traffic and crashed into them.

A 67-year-old woman was trapped against the café wall by the impact of the car.

Paramedics promptly attended to her at the scene before she was transported to Royal Prince Alfred Hospital. She is in serious yet stable condition, with injuries to her leg and hip.

The second customer narrowly avoided the car’s path but was knocked to the ground in the commotion.

Security footage captured the dramatic scene as the vehicle mounted the curb, causing onlookers to rush forward in an urgent effort to prevent further harm to the café’s patrons.

Reports suggest that the driver, a man in his 30s, had fallen asleep at the wheel.

“We started banging on the window saying ‘wake up, wake up, wake up’ and there was no response,” witnesses told 9News.

Witnesses rushed to the aid of the victim and helped pull her out from the crash scene, as other bystanders ordered the driver out of the car.

However, the man was seen rustling through items on the passenger seat before getting back into the car and fleeing the scene.

Police located the car just 600 metres away on Darley Road and arrested the driver, who was also taken to Royal Prince Alfred Hospital under police guard for an assessment.

Police are investigating the circumstances surrounding the crash.