Great Britain's Andrew Mullen has missed out on a medal in the S5 50m butterfly final after touching fourth.
The top three were some way ahead of the rest of the field, but there was a battle for gold and silver.
Brazil's Daniel Dias claimed gold, but it took a world record time of 34.15s to beat United States' Roy Perkins, who timed in at 34.57s.
Bronze went to He Junquan of China, who was a few seconds back with 37.20s.