SINGAPORE - The angry man had yanked and broken the door handle of the taxi as he tried to get in.
When the cabby refused to drive him, and called the police, the passenger allegedly went berserk, raining blows on him until he lost consciousness.
The attack happened on Wednesday, at about 9am outside a hotel in Pasir Panjang.
The cabby, Mr Tan Chon Siang, 48, was taken to the National University Hospital, where he was warded overnight.
Mr Tan, a Comfort cab driver, told Shin Min Daily News that the man is Korean, and looked to be in his 30s.
He said the man had left the hotel in a huff, with three luggage bags in tow.
Mr Tan said he threw the bags into the boot of the taxi, then shouted to be driven to the airport.
The cabby said that he told the man to calm down, hoping to dispel his temper. But the man just slammed the car boot shut.
He then tried to board the cab, but allegedly yanked at the door handle of the vehicle so violently that the handle broke off.
Mr Tan said the man then walked over to the other door, tossing the broken handle aside.
"He used too much strength, and broke the door handle! He then scolded loudly that the car is lousy," the cabby said.
Uncomfortable ferrying such an emotionally charged passenger, Mr Tan said he called the police, removed his car keys from the ignition, and walked to the hotel entrance and waited for the police to arrive.
He said: "The man got out of the taxi, and asked me why I wasn't driving. When he realised I was taking pictures of him, he rushed towards me."
Mr Tan ran, but was no match for the younger man, who tackled him.
The man allegedly knocked off Mr Tan's spectacles, and punched his head and back repeatedly.
Mr Tan then lost consciousness.
The cabby said he later came to his senses and saw the man rummaging around the taxi driver's seat, presumably looking for the car keys.
Said Mr Tan: "I forced myself to stand, and when I saw him charging towards me, I immediately knelt, covering my head with my hands, and asked him to stop hitting me.
"It was only then that he stopped."
He added that hotel staff, after witnessing the attack, called to him to hide in the hotel building.
Mr Tan feared the man would escape because he was already removing his luggage from the car boot, but the police got there in time.
The man was arrested at the scene.
Police confirmed the incident. A spokesman told The New Paper: "Upon police's arrival, a man was arrested as he was believed to be of unsound mind."
Police are investigating the incident.
Ms Tammy Tan, group corporate communications officer of ComfortDelGro Corporation, expressed shock at this incident.
She said: "We certainly do not condone passengers displaying such aggression towards our cabbies, especially since our cabby had done nothing to provoke the passenger in this instance.
"Our immediate concern is the well-being of our driver. We have visited him in hospital and will be assisting him as best we can with his medical claims."
The company will also be assisting in ongoing police investigations.
This article was first published in The New Paper.