He chanced upon her profile on Facebook and they started talking on instant messaging app WeChat.
Not long after, she offered him sex for $100.
The 23-year-old kitchen assistant, who declined to be named, arranged to meet the woman last November.
Before their meeting, she told him to make an advance payment of 500 yuan (S$106) by buying Alipay credits, which he did on an AXS machine.
Without delivering what she had promised, she then requested another 3,000 yuan worth of Alipay credits.
He thought that he would then get to have sex with her, but a man called him, asking him to pay a "refundable" sum of 5,000 yuan to ensure that the customer was not with the police.
He obliged but never got to meet the woman.
When a second man claiming to be the woman's boss called and asked for $1,000, he finally decided to break off communications and file a police report.
He has not heard from the woman since.
The man is one of more than 1,200 people who fell victim to credit-for-sex scams last year.
Most of the victims were aged between 20 and 39.
Seow Bei Yi