Angry at being told off for eating in a taxi, a bartender punched the taxi driver while he was driving.
This took place in the early hours on Sept 4 last year in Lower Delta Road.
Cabby Philip Do Chiong Yu, 51, then pressed the distress button in the taxi, but continued driving.
When he told the passenger, Azhar Abdullah, that he was going to drive him back to Liang Court where he had boarded the taxi, the 36-year-old threw a few more punches at the cabby.
This second attack knocked off and broke Mr Do's spectacles, leaving him with a cut near the left brow.
Deputy Public Prosecutor Senthilkumaran Sabapathy told a court that after Mr Do was punched the second time, he kept driving, enduring the pain.
When the taxi was at the yellow box junction of Clemenceau Avenue and River Valley Road, Azhar jumped out of the vehicle. Shortly afterwards, he was arrested.
Yesterday, Azhar was sentenced to three months' jail each for hurting Mr Do and stealing two bottles of Skyy Infusions Vodka totalling $394 with a female friend at China One club at Clarke Quay on Jan 23 this year.
A charge of rash act to endanger the personal safety of another was taken into consideration.
Azhar had previous convictions for robbery, disorderly behaviour, using abusive language towards a public servant and drug-related offences.
Noting his bad criminal history, District Judge John Ng said it was possible to send him for corrective training, which is a minimum of five years.
Azhar was allowed to defer his six-month jail sentence until Sept 16.
He could have been jailed up to two years and/or fined up to $5,000 for causing hurt. For theft, the maximum penalty is seven years' jail and a fine.