Her plan was to qualify for Monday's semi-final, but instead, South Africa's Tatjana Schoenmaker not only qualified, she also broke the current Olympic record.
During her heat in the women's 100m breaststroke, Schoenmaker was in the lead in lane 5 when she realised that her competitors were catching up with her.
"I obviously saw that they were catching up a bit at the end and I was getting quite tired… I didn't expect that, very happy with that as a first race."
Her time of 1:04.82 shocked the world's best swimmers as it was her Olympic debut as well.
"I didn't expect that at all. When I saw I was ahead, I thought I was dying because I was going way too fast at the end and I though I could just try and hold on," Schoenmaker told News24 after her record-breaking performance.
The semi-final will take place on Monday.
So far, Schoenmaker has been the only hope for a medal for Team South Africa.
Watch the Media Gist video below for more on how Tatjana Schoenmaker won her heat in the women's 100m breaststroke and set a new Olympic record in Tokyo.
Image credit: Swimming World