Today Sarah Sjöström made her annual debut after her hard training period in South Africa.

In the distance 50 meters butterfly, she showed class and won by over a second - against the rather anonymous starting field in general - as she swam in at 25.12.

Sjöström's competition debut today was the first of the really tough program this weekend where she will go through five branches in three days.

- Sure I'm a little tired, but at a good level. I feel ready physically and mentally, the 26-year-old said before the competition debut where she also pointed out that it was technology that was important this weekend.

- It would be nice to get out of here with fast times, but above all I will look at technical details such as the number of armrests, how far I get on each armrest and if the turn is better in the butterfly, she says.

The track in Luxembourg is also the one that Sarah Sjöström set her junior record for 100 butterfly in 2007.