The Belarusian missed one shot on the range but was just quick enough to hold off Germany's Franziska Hildebrand, who had shot clear, by half a second.
Italy's Laura Vittozzi took third 5.5 seconds behind Domracheva, who won women's relay gold at the recent Winter Olympics.
Anastasiya Kuzmina maintained her lead at the top if the sprint standings despite only finishing 30th, with the Czech Republic's Veronika Vitkova now just 19 points back in second.
Domracheva's wins the women's sprint in Kontiolahti
And in the overall World Cup standings, Kaisa Makarainen extended her advantage over Kuzmina, she now has 623 points, 35 clear of the Slovakian in second, with Dorothea Wierer third, 40 points further back.