The PM finished her speech at the Orsted wind turbine complex in Grimsby, where she addressed Brexit and parliamentary voting on a deal with the EU, and was on her way out when she got one last question by a woman reporter.
"Only one question from a woman reporter on International Women's Day. It's a pretty poor show, isn't it?" the journalist said.
As Theresa May turned around, she delivered a feisty comeback, which was followed by a round of applause from the audience.
"You've had answers from a woman Prime Minister," Mrs. May said.
In response, social media erupted with a flood of comments:
On the International Women's Day, the Prime Minister met with female entrepreneurs at Downing Street to discuss, among other issues, female genital mutilation.