South Africa's Roland Schoeman won the men's 50m freestyle in a thrilling race.
Australia's Brett Hawke, who was leading after 25m, was edged out by 0.01 seconds into silver while defending champion Mark Foster of England finished with bronze, in a time of 22.47.
After the race, Foster told the BBC he was very disappointed about the result and admitted he was preoccupied with worries over his wet suit.
"I was awful," he said.
"I put the suit on this evening but I'm too conscious of wearing this and not breathing properly because it's too tight.
"I felt fantastic a week ago but I felt worse all the way through.
"I've been faster than that three times at competitions that aren't important."