Ukraine Paralympian Iaroslav Semenenko has kicked off his campaign with an impressive win in heat one of the men's 100m SB backstroke.
The 25-year-old, who has no arms to aid him in the race, soared through the swim in 1:18.24, with Sebastian Iwanow for Germany recording the second-fastest time.
Semeneko had the best start out of the blocks in the S6 heat and is likely to be joined by Australia's Matthew Haanappel, who set a time of 1:24.02, in the final.
Ivanildo Vasconcelos of Brazil finished last in the first race at the Aquatics Centre of the Paralympic Games with a time of 1:37.68.
