Tokyo: Rio Olympic champion Adam Peaty defended his title in men's 100m breaststroke on Monday, winning the gold medal in 57.37 seconds.
The three-time world champion had a convincing lead over silver medalist Arno Kamminga of the Netherlands, who finished 0.63 seconds behind.
The bronze went to Italian Micolo Martinenghi. The 21-year-old touched home in 58.33.
Margaret MacNeil of Canada touched home first in 55.59 seconds to win the women's 100m butterfly gold at the Tokyo Olympic Games on Monday.
Fresh from winning a silver in women's 4x100m freestyle on Sunday, the 2019 world champion edged China's Zhang Yufei by a close 0.05 seconds to win her maiden Olympic title.
Zhang, finishing first in the semifinals, settled for a silver in 55.64 seconds. Australia's Emma McKeon, who finished 8th at Rio 2016, took a bronze in 0.08 seconds.
Australia's world champion Ariarne Titmus edged world record holder Kathleen Ledecky of the United States to claim gold in the women's 400m freestyle at the Tokyo Olympic Games.
The Aussie beat Ledecky to second in the last 100m, winning in an Olympic record time of three minutes and 56.69 seconds.
Rio Olympic champion Ledecky took a silver in 3:57.36 and China's Li Bingjie bagged the bronze.
Li set a new Asian record at 4:01.08, thanks to a 29.47-second final lap that saw her overtook Canadian Summer McIntosh.
Her compatriot 17-year-old Tang Muhan finished fifth.