Five-time Olympic gold medalist Kaylee McKeown was cleared to compete in the 50m backstroke final at the Australian trials on Monday after she successfully appealed her disqualification in the heats.
The 23-year-old world record holder finished first in her heat, but her time was not displayed on the board, and she was ushered away in tears by officials after being called for an early start.
However, McKeown's team lodged an appeal and, after an anxious wait, she was given the green light to compete in the final, which closes out the opening day of the trials in Adelaide.
The trials serve as Australia's qualifiers for the July 11-August 3 world championships in Singapore.
"(McKeown) was disqualified after being ruled to initiate an early start from lane four of heat one but her protest was upheld after officials ruled in her favor that she was distracted by a movement immediately prior to the signal," Swimming Australia said.
"Her time of 27.27 made her the fastest qualifier tonight with good mate Mollie O'Callaghan second fastest with 27.72 - both under qualifying time for Singapore World Championships."
McKeown became the first woman to retain the 100 and 200 backstroke Olympic titles at last year's Paris Games.