Polytechnic student Joyce Seah, 18, won the solo singing category at the third edition of the National Schools Xinyao Singing and Songwriting Competition.
This follows her win in the group singing category of the same competition last year.
The finals, which were attended by a 1,300-strong audience, were held last Saturday at Singapore Polytechnic, which also produced winners in two out of three categories.
Ms Seah, a food science and technology student from the institution, wowed the judges with her jazzy, upbeat cover of Hong Shaoxuan's Farewell Sleeve, then switched moods to deliver Tanya Chua's emotional ballad A Hundred Thousand Teardrops.
Her fellow Singapore Polytechnic students Wayne Oh Geng Hui and Jeremy Hwang Jie Wei bagged the prize for best composition with their song Unforgettable Past, which was performed by their friend Brandon Ling. All three are 19 and pursuing diplomas in music and audio technology.
The group singing category was won by River Valley High School duo Coffee And Tea, comprising Liu Yifei, 18, and Fion Chai Xin Yi, 17, who performed Liang Wern Fook's Friendship Forever and Let The Night Fall Gently.
A record number of young singers and songwriters took part in the contest this year.
The number of new songs written for this year's competition was 75, more than double last year's, while the solo singing category saw 109 participants, up from 85 the year before.
The competition is meant to promote xinyao, a Singapore Chinese indie folk music movement popular in the 1980s and 1990s, among younger generations.
It was organised by the Committee to Promote Chinese Language Learning (CPCLL) and Chinese-language daily Lianhe Zaobao, together with TCR Music Station, mm2 Entertainment and Jurong Junior College.
The judges, who included xinyao veterans such as Jimmy Ye, Roy Loi and Pan Ying, praised Ms Seah's song choices and said her vocals sounded like those of Tanya Chua, one of Singapore's most acclaimed Mandopop artists.
Ms Seah said she was so shocked when she heard her name announced as the winner that she almost cried.
"I was so tired while practising that I would sometimes throw a little tantrum, but my family and friends supported me throughout," she said.
The winning composition Unforgettable Past's angst-ridden lyrics about a break-up prompted many to question songwriter Mr Oh if it is based on personal experience, but he was quick to demur.
"I prefer to write about things that happen to other people," he said. "I am inspired by the Chinese television shows I watch."
He and his team hope to pursue careers in music and would like the xinyao culture to take deeper root among their generation.
Mr Ling said: "As Singaporeans, it's something we ought to let evolve. These songs were made by older generations for us and we should keep building this culture."
Guest-of-honour Ng Chee Meng, Minister for Education (Schools), presented the prizes.
He said in Mandarin: "The standard of tonight's xinyao student performers was very high and I'm full of awe.
"I feel that singing xinyao, writing xinyao and listening to xinyao can attract more students to learning Mandarin. It is a valuable cultural resource for Singapore."
Prizes for this year's competition amounted to $18,000, with the winning solo singer receiving $1,000 in cash, while the top prizes for the group singing and songwriting categories were $1,500 each. Winners also got return SilkAir tickets to destinations in Australia, Laos and China.
The competition is open to students in secondary schools, pre-universities, polytechnics and the Institute of Technical Education.
Local singer Nathan Hartono, who is the ambassador for CPCLL, made a guest appearance at the finals with acoustic renditions of Mavis Hee's Moonlight In The City and JJ Lin's Song For Nobody.
In between his sets, the Sing! China first runner-up last year urged youngsters like himself, who do not come from a Mandarin-speaking background, to persevere in learning the language and practising it with others.
He added that he was returning to Beijing the day after to work on his new album, for which he has already recorded three songs. "Perhaps next year's contest will have students singing my songs," he quipped.