An argument between two taxi drivers turned violent when one of them ignited the stream of liquid from an aerosol can and aimed the flames at the other cabby.
The flash fire lasted three seconds and left Mr Lam Choon Chai, 61, with first-degree superficial burns to his left ear, cheek and neck.
His attacker, Ng Soon Kim, was sentenced to a year and two months' jail yesterday after pleading guilty to an assault charge.
The 65-year-old was also disqualified from driving all classes of vehicles for 11/2 years and ordered to compensate Mr Lam $115 for hurting him.
The incident happened on May 1, 2017, at about 8pm. Mr Lam was in his vehicle, waiting in line at a VivoCity taxi stand, when Ng's taxi abruptly cut into his lane.
Deputy Public Prosecutor Grace Chua told the court that this almost caused Mr Lam's taxi to hit a wall.
He did not confront Ng at this point and both cabbies later picked up their passengers.
The two men then drove towards the traffic light junction of Harbourfront Walk and Telok Blangah Road, where they stopped their vehicles when the lights turned red.
Seeing that Ng's vehicle was next to his, Mr Lam wound down his front passenger seat window and hurled vulgarities at the older man.
DPP Chua said: "The accused then alighted from his taxi, taking a can of insecticide from his cab with him.
"He then stretched his hand into the victim's taxi through the open front passenger seat window, pointed the can of insecticide at the victim, before spraying the insecticide twice at the victim.
"The accused held the can of insecticide approximately 30cm away from the face of the victim when he sprayed the insecticide at the victim."
Some insecticide entered Mr Lam's eyes, hurting him, when Ng sprayed a second time.
Mr Lam's passenger then shouted at Ng, the court heard.
Undeterred, Ng returned to his taxi to retrieve a lighter.
He then ignited the stream from the aerosol can, causing Mr Lam to be injured.
Mr Lam later alerted the police and an ambulance took him to the Singapore General Hospital.
Ng is now out on bail of $5,000 and was ordered to surrender himself at the State Courts on Feb 19 to begin serving his sentence.