A private-hire bus driver spiked his flatmate's drinking water with what he thought was a sleeping pill because he wanted to rape her.
When the 21-year-old woman drank the tainted liquid, she found it tasted bitter and spat it out.
Indian national Annadurai Prabakaran, 28, was yesterday sentenced to two years and 10 months' jail and three strokes of the cane.
He had pleaded guilty to one count each of administering a drug to the woman and obstructing the course of justice.
Annadurai, who has worked in Singapore for more than seven years, lived in a Tampines flat with the woman, who is also an Indian national, and her uncle's family.
Deputy Public Prosecutor Rachel Tan said Annadurai had fantasised about the woman but did not think she would agree to have sex with him as they had never spoken to each other.
He then hatched a plan to drug the woman before raping her while she slept.
On Dec 9 last year, he went to Geylang and paid $2 for two pills from the owner of a makeshift stall.
The court heard the pills contained sildenafil - the active ingredient in Viagra which is used to treat erectile dysfunction.
Three days after he bought the pills, Annadurai grabbed the chance to spike the woman's unattended bottle of water when they were alone at home. The other occupants were in India.
After slipping one pill into the bottle, he went to his room to wait. But the woman realised something was amiss and spat out the drink.
Frightened, she phoned her uncle's friend and tearfully told her what had happened.
The 36-year-old friend turned up with a 41-year-old man soon afterwards and noticed that the victim's drinking water appeared cloudy.
When confronted, Annadurai admitted slipping a pill into the bottle of water and begged for forgiveness. But while the woman and her two guests were standing in the corridor in front of the flat, Annadurai suddenly snatched the bottle from her and tried to empty its contents.
However, there was still some water left inside the bottle when he dropped it on the floor. The older man picked up the bottle and alerted the police.
An analysis by the Health Sciences Authority later revealed that the water contained sildenafil.
Yesterday, Annadurai's lawyer, Mr Kalaithasan Karuppaya from Grace Law, pleaded for his client to be given the minimum possible sentence. He also said Annadurai was remorseful and had acted out of character.