A valet at Sydney's Hyatt Regency hotel had a bad day at work on Thursday after he accidentally parked a Porsche Carrera underneath another vehicle.

While attempting to park the Porsche, the car reportedly accelerated and ended up under an orange sports utility vehicle (SUV).

Police were called to the hotel to cut out the driver, who was unharmed, as onlookers were treated to the comical sight of the black soft-top Porsche squashed under the larger vehicle.

"When I first saw this, I thought that it was being shot for a TV show or a movie, but apparently it's real," said bystander Jonathan Bayle.

A witness told the ABC: "I heard this revving and this bang and turned around and the Porsche was literally underneath this other car. It was crazy."