Author NK Jemisin has scooped her third Hugo award for best science-fiction novel and, in doing so, has become the standard-bearer for a sea change in the genre’s diversity, as women – especially women of colour – swept the boards at last night’s ceremony.

Taking the stage to accept her third win in three years for her novel The Stone Sky, Jemisin told the audience at the 76th World Science Fiction Convention in San Jose, California, on Sunday that “this has been a hard year … a hard few years, a hard century,” adding: “For some of us, things have always been hard, and I wrote the Broken Earth trilogy to speak to that struggle, and what it takes to live, let alone thrive, in a world that seems determined to break you.”

In 2016, Jemisin became the first African American to win the best novel category for The Fifth Season, repeating the achievement again in 2017 for its sequel, The Obelisk Gate.

On making it a hat-trick with The Stone Sky, the third book in her Broken Earth series, Jemisin said: “As this genre finally, however grudgingly, acknowledges that the dreams of the marginalised matter, and that all of us have a future, so will the world.”

NK Jemisin’s acceptance speech at the 2018 Hugo awards.

Jemisin’s success has heralded an increasing shift away from science fiction and fantasy being dominated by white male authors. Other winners at this year’s Hugo awards include Rebecca Roanhorse, who won best short story for her Native American tale Welcome to Your Authentic Indian Experience; Suzanne Palmer’s The Secret Life of Bots, which scooped best novelette; and Martha Wells’s All Systems Red, which won best novella.

Veteran writer Lois McMaster Bujold, herself a four-time best novel winner, won the best series award for her World of the Five Gods sequence. The comic series Monstress, written by Marjorie M Liu and illustrated by Sana Takeda, was named best graphic story, with the latter also scooping best professional artist.

A giant of science fiction and fantasy, Ursula K Le Guin, who died in January aged 88, won best related work for her book of essays, No Time to Spare.

There were also wins for the Patty Jenkins-directed Wonder Woman movie, DAW Books’ Sheila Gilbert as best long-form editor, and Lynne M Thomas and Michael Damien Thomas jointly getting the best short-form editor award.

Two other awards, not part of the main Hugo selections but administered by Worldcon, went to Rebecca Roanhorse again (the John W Campbell award for best new writer) and Nnedi Okorafor for Akata Warrior (best young adult book).

The diversity of this year’s Hugo awards signals an end to influence of the Sad and Rabid Puppies, two groups of rightwing and conservative science-fiction and fantasy fans and authors that attempted to nominate authors who they felt were not “overtly to the left”. In 2015 and 2016, “No award” was given in multiple categories, in order to avoid rewarding the Puppies’ nominees. Last year was the first time not a single “no award” was given, since the two groups formed.