Sjöström started the day with a victory in the 100 meter freestyle, the time 51.32.
National team colleague Michelle Coleman, who swims for the Toronto Titans during the ISL, was fifth in the race with 53.09.
Sjöström's previous back problems, which arose after the first match in ISL and forced her to stand over competitions earlier this week, meant that she swam fewer branches than usual.
But the result was one hundred percent with victory in all races she competed in, both yesterday and today.
- It will not be as tough a program as in my first race, then I ran nine disciplines, it will be much smaller than that.
I just want to check the situation how the back can handle the load, Sjöström told SVT Sport earlier this week.
Impressive display of 50 free
After the victory in the 100 freestyle, Sjöström then had a powerful performance in the 50 m freestyle competition.
Skins is a form of knockout competition with eight swimmers from the start in round one, the top four advance to round two where additional swimmers are eliminated - and the two most placed meet in the final.
For the finalists, it is thus about three maximum races within the race of just a few minutes.
Sjöström went undefeated straight through the leather competition and won the final in a convincing way, winning time 23.72 - 88 hundredths before former Olympic gold medalist Ranomi Kromowidjojo from the Netherlands.
Third place for Hansson
Lousie Hansson took third place in the 100 meter medley with a time of 59.09.
Louise Hansson swims with national team colleagues Erik Persson and Michelle Coleman for the team Toronto Tritans who finished third in the team competition today which was won by Energy Standard with team captain Sjöström.
KLIPP: Sjöström won directly in the ISL comeback (5 Nov 2020)
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Sarah Sjöström is back in the ISL pool.
Photo: Bildbyrån