It is second time lucky for author Sebastian Sim, who walked away with $25,000 after winning the third Epigram Books Fiction Prize yesterday.

The office executive, 51, won Singapore's richest literary prize with his manuscript The Riot Act.

He was a finalist for the inaugural prize in 2015 for comic novel Let's Give It Up For Gimme Lao!, but lost to O Thiam Chin's Now That It's Over.

He said: "I practised being disappointed two years ago, so this year, I decided to lower my expectations. This has been a big surprise and I can't stop smiling."

The Riot Act, set in the aftermath of the 2013 Little India riot, is a fictional tale about three women whose lives intertwine because of the event - from Hashwini, who fears her actions may have triggered the chaos, to Sharon, who plans to take advantage of it to boost her political career.

Described as a "fast-paced romp", it follows in the same comic vein as Gimme Lao and looks at the way the truth was distorted and reworked to fit different agendas in the wake of the riot.

A theme Mr Sim wanted to explore was "how difficult it is to maintain one's integrity and practise honesty when circumstances promise to reward you if you will just bend your principles a little".

Mr Sim, who published three wuxia (martial arts) novels in Chinese between 2004 and 2012, has also worked as a bartender, a prison officer and a croupier.

The winner of the prize, which is for unpublished English-language novels, was announced at an award ceremony and gala dinner held at the Conrad Centennial Singapore hotel. Forty-seven submissions were received this year.

One of the judges for the prize, Singapore Literature Prize-winning poet Cyril Wong, said the decision was not unanimous and had taken many hours, adding that each manuscript had its "more than memorable moments".

He called Mr Sim's work a "surrealistic retelling that strikes at the heart of cynicism driving Singapore's culture wars" and "holds up a tilted mirror to everything wrong with our society".

The Riot Act will be published next year by Epigram, as will the manuscripts of this year's three other finalists.

They are Nimita's Place by The Straits Times arts correspondent Akshita Nanda, 38, which follows two women with the same name living 70 years apart in India and Singapore; 9th Of August by The New Paper assistant news editor Andre Yeo, 45, about a terrorist attack on National Day in 2020; and Sofia And The Utopia Machine by 31-year-old writer Judith Huang, a speculative work about a teenage heroine and set in a futuristic Singapore.

The three first-time novelists will receive a cash prize of $5,000 each.