Welson Sim, 19 , celebrates his victory in the 400m freestyle event. He finished with a timing of 3:50.33, meeting the A timing for Rio Olympics. (Photo 2 © Chua Kai Yun/Red Sports)

Welson Sim, 19, celebrates his victory in the 400m freestyle event. The Malaysian defending SEA Games champion in this event finished with a timing of 3:50.33, meeting the ‘A’ qualifying mark for the Rio Olympics. (Photo 2 © Chua Kai Yun/Red Sports)