Tirthank Pegu delivered the India's best-ever swimming performance at the Youth Olympics in Dakar, Senegal on Sunday.The 16-year-old swimmer from Assam clocked 54.98 seconds in the final, to finish fourth by just 0.27 microseconds in men's 100m butterfly.He is only the second Indian swimmer to advance to the final after Srihari Natraj finished sixth in the men’s 100m backstroke final in 2018.