His fellow cabby pushed, punched and even taunted him.
Furious, Choo Ng Lye Choon , 65, lashed out at Mr Lim See Ann, 47, with a blade and cut him.
Yesterday, Choo was sentenced to one week's jail and a $2,500 fine after pleading guilty in a district court to causing hurt on grave and sudden provocation.
Choo was originally charged with causing hurt with a weapon, which carries a jail term of up to seven years. But the charge was reduced as the victim was the initial aggressor.
The men were driving their respective vehicles along Beach Road near The Concourse at around 3am on April 22 last year when Mr Lim suddenly cut in front of Choo and stopped.
Court documents did not specify any accident. But Mr Lim asked Choo for an unspecified amount as compensation, though there was no visible damage on both vehicles.
When Choo refused, Mr Lim turned aggressive and pushed his left shoulder twice. He then removed Choo's vehicle key from the ignition but the latter managed to snatch it back.
After Mr Lim challenged him to a fight, Choo went to the passenger side of his taxi and retrieved a Swiss Army knife with a 6.5cm blade.
Choo did not brandish the weapon at the other cabby, but pleaded with him to stop bothering him.
However, Mr Lim continued pestering Choo for compensation and punched Choo on his left cheek.
Said Deputy Public Prosecutor Teo Lu Jia: "Choo came out of the taxi with the Swiss Army knife. Both of them then continued arguing with each other.
"Mr Lim challenged Choo and taunted Choo, saying that Choo was old and that he could beat Choo up."
Furious, Choo used the knife to stab and slash Mr Lim's upper body.
Another cabby who happened to be driving by broke up the fight.
Mr Lim was taken to hospital with wounds on his neck, chest, left upper arm and right hand. He was warded for one day and given 15 days of hospitalisation leave.
Mr Lim received a police warning for his role in the fight.
Choo is out on $15,000 bail. He will start his sentence on Feb 13.