She was the fastest in the 100 meter backstroke trials in a time of 56.04, just over a tenth ahead of the nearest chaser, the Canadian Ingrid Wilm.
Also at the same distance is Hanna Rosvall, who with 56.57 was fourth fastest.
They both swim semi-finals later in the morning, Swedish time.
So does Sara Junevik, who was the fastest in her trial heat in the 50 meter butterfly, and is thus easily ahead in 25.04.
The Swedish women’s relay team is also further in the 4×100 meter freestyle and will swim the final later in the afternoon.
18-year-old Emelie Fast did not advance in the 200 meter medley with a time of 2.10.95.