China's Peng Qiuping smashed her own world record to win gold in the women's 50m backstroke S3 at the Rio Paralympics here.The 22-year-old clocked 48.49 seconds at the Olympic Aquatics Stadium on Sunday to beat her previous record of 49.91, Xinhua news agency reported.Fellow Chinese swimmer Meng Guofen took silver in 51.42 and Lisette Teunissen of the Netherlands claimed bronze in 53.44.Peng, who suffers from impaired muscle power, also won gold in the mixed 4x50m freestyle 20 points at the ongoing Paralympics.