The teenager needed someone she could confide in about her personal problems, but a manufacturing manager, now 42, had other ideas after befriending her on social media platform WeChat.
Having gained the girl's trust, Singaporean Ian Kevin Bligh invited the 15-year-old to his home while his wife was at work. He then had sexual intercourse with the minor.
In his submissions, Deputy Public Prosecutor Raja Mohan told the court that the girl "was scared and struggled to process what was happening". On another occasion, Bligh gave her a glass of vodka before sexually penetrating her.
The offences took place between May and November 2014.
DPP Raja said: "The victim trusted the accused and was sufficiently comfortable to share her personal problems - about her fights with her father and classmates - with him. The victim was unequivocal that she did not harbour any romantic feelings for the accused."
On Tuesday, after a six-day trial, District Judge Tan Jen Tse found Bligh guilty of two counts of sexual penetration.
In his submissions, DPP Raja said the girl, now 19, did not like to be at home as she was not close to her father, stepmother and two step-siblings. The teen, who is of borderline intelligence, also got into arguments with the boys in her Secondary 3 class almost daily because they irritated her. She felt that as a prefect and class monitor, she was being targeted by her classmates. As a result, she did not like going to school.
The DPP added that the teenager felt that she was unable to talk to her father about her problems.
In Bligh, she thought she found someone to chat with and shared with him her age, hobbies and personal problems. But he took her virginity, the girl had testified.
She stopped all contact with him in November 2014 after she had a boyfriend. She also kept what happened a secret, fearing her "hot-tempered" father would find out and beat up Bligh.
The incident only came to light when her teacher found her using her mobile phone in class on Jan 14, 2015. On checking her phone, the teacher found messages between the girl and her boyfriend.
Suspecting that the two had engaged in sexual activities, the matter was referred to the police. It was during police investigations that Bligh's offences were uncovered, said the DPP.
Bligh was offered bail of $10,000 and will be back in court on Oct 4.