American novelist Tayari Jones’s portrait of a young African American’s wrongful incarceration, and its devastating impact on his marriage has beaten two Booker prize winners to take the Women’s prize for fiction.

Described by chair of judges Kate Williams as a book that “shines a light on today’s America”, Jones’s fourth novel An American Marriage won the £30,000 award on Wednesday night. With fans including Oprah Winfrey and Barack Obama, the novel follows ambitious newlyweds Celestial and Roy. “We’re not your garden-variety bourgeois Atlanta Negroes where the husband goes to bed with his laptop under his pillow and the wife dreams about her blue-box jewelry. I was young, hungry and on the come-up. Celestial was an artist, intense and gorgeous,” it begins.

Their lives together are just beginning when Roy is sentenced to 12 years in jail for a rape he hasn’t committed. Celestial believes in his innocence, but finds herself taking comfort in her childhood friend Andre until five years later, Roy’s conviction is overturned and he returns home.

The novel won from a six-book shortlist that included last year’s Booker winner, Anna Burns’s Milkman, and former Booker winner Pat Barker’s new novel, The Silence of the Girls. Williams said judges deliberated for four hours to make the tough decision.

“It’s an incredible examination of America and American life, focusing on the intimacy of a marriage but on a huge political canvas,” she said. “The prose is luminous, striking and utterly moving. How hard it is even when you’re on the outside and are free, how you’re not really free when you have someone in prison.”

Jones said: “I am thrilled and honoured. I wasn’t expecting to win. The shortlist was so strong and I was honoured to be among them but I had no idea whether I would win. I didn’t write a speech!”

Incarceration is the “boogeyman of black America,” she added. “I decided to look under the bed and tackle it head on.”

With her win coinciding with Donald Trump’s trip to the UK, Jones said she had no desire for the president to read her novel.

“I’m delighted that Obama read my book and I’m delighted that I had a president in my time that read books and recommended them, who cared about the past and history, who used it to guide us to the future. I have no real hope or desire that the current occupant of the White House will read my book.”

The whole shortlist was timely, added Williams, from Barker’s retelling of the Iliad from the perspective of a princess who is made a slave to Achilles, to Madeleine Miller’s twist on Homer’s witch, Circe. An American Marriage also has links to Greek myth; Jones told the Guardian that every novel she has written “harks back to the Greeks”, with Celestial being a twist on Penelope, the faithful wife who waits for years for Odysseus – “only modern, independent and famous for her art”.

Williams said: “All the shortlisted novels speak clearly about the lives of women in different ways, about oppression and identity and trying to be free in a regime that doesn’t want you to be.”

Jones, a novelist and a creative writing professor who lives in Brooklyn, has spoken of finding inspiration in an argument she overheard while she was doing research at Harvard into mass incarceration.

“The woman, who was splendidly dressed, and the man – he looked OK. But she looked great! And she said to him, ‘You know you wouldn’t have waited on me for seven years.’ And he shot back, ‘This shit wouldn’t have happened to you in the first place’,” Jones told the Paris Review last year. “And I was like, ‘You know, I don’t know him, but I know she’s probably right. I doubt very seriously that he would wait on her for seven years, and he is probably right that this wouldn’t have happened to her … I was intrigued by them, and so I integrated this very personal conflict with the research I had done.”

Williams expressed the hope that – with Obama’s successor currently in the UK – that An American Marriage might find another presidential reader. “It’s very timely given we have the president of America in this country at present. Let’s hope he and the first lady read the book,” she said.

The Women’s prize is the UK’s only book award for fiction by women. Running for 24 years, it has been won by writers including Zadie Smith and Lionel Shriver.