Olympian Grant Hackett has earned a spot on Australia's World Swimming Championships relay team after six years away from the sport.
The 34-year-old, who won 1500m freestyle gold at the 2000 and 2004 Games, returned to training six months ago after coming out of retirement.
He needed a top-six finish in the 200m final at the nationals in Sydney to win a place at July's tournament in Russia.
And he finished fourth in a time of one minute 46.84 seconds.
Hackett rose to prominence at the same time as Ian Thorpe and endured a long-standing rivalry with his compatriot, who won nine Olympic medals, including five golds, 10 Commonwealth Games titles and 13 World titles.
Thorpe himself made an unsuccessful comeback bid for the London 2012 Olympics, at the age of 29.