An intruder made an unwelcome splash when he invaded the final of the men's 10m platform final, won by Tom Daley at the Diving World Series.
The young man evaded security staff to make a dash for the diving boards at the London Acquatics Centre on Sunday night.
He pulled off his tracksuit to strip to Speedos as he rushed up the stairs, closely followed by the guard.
But he could not be stopped and jumped into the pool - to boos from the crowd.
The man was greeted with perplexed looks from the judges before being led away by security.
Daley, the Olympic bronze medallist, won gold in the 10m platform event.
He picked up the highest score of the final, with 102.60 in the fifth of his six dives on his way to winning gold ahead of Chinese duo Jian Yang and Bo Qiu.