File photo of Tang Qianting. Paris Olympic champion Regan Smith of the United States triumphed in the women's 100m backstroke final in 54.55 seconds, a new championship record. The men's 100m backstroke event delivered a thrilling final, where Russia's 18-year-old Miron Lifintsev, competing as a neutral athlete, emerged victorious with a new world junior record of 48.76 seconds. In the …