Pallister gold rush with record relay swim

Lani Pallister has won her third gold medal, anchoring Australia to a world record in the women's 4x200m freestyle relay at the world short course championships in Melbourne.

Earlier on Wednesday night the 20-year-old won gold in the 800m after opening the titles with a 400m victory, and she was able to back up with a stunning final leg to steer the home team to victory.

It comes after the Australians also smashed the world record in the 4x100m freestyle relay 24 hours earlier.

They were also able to do it without superstar Emma McKeon, who opted not to race to concentrate on her individual program.

Madi Wilson led the team out handing over to Mollie O'Callaghan, who had battled cramps before the race after winning a silver medal in the 100m backstroke.

Leah Neale kept the Australians in front through the third leg before Pallister secured the gold in a time of 7 minutes 30.87 seconds, eclipsing the Dutch mark of 7:32.85 set in 2014.

Canada were second in 7:34.47 while the USA won bronze in 7:34.70.

"I was a bit nervous because I didn't know how my body would react after the 800m but it's something I've been training for," Pallister told Nine.

"To come away with a gold medal and a world record is something I've dreamed of."

The daughter of former Australian distance swimming great Janelle Elford, Pallister took control of the 800m race from the get-go.

With four laps to go her lead was out to half a pool length before she touched the wall in 8 minutes 4.07 seconds, which was 6.34 seconds ahead of the field.

It also beat her personal best by more than three seconds.

The Queenslander's world championship success has come after she considered giving the sport away following heart surgery as well as battling an eating disorder and glandular fever over the past two years.

Kaylee McKeown added another gold medal to the Dolphins' haul, pipping teammate O'Callaghan to win the 100m backstroke.

World record holder in the long course 100m backstroke, McKeown who swam in lane seven, touched the wall in 55.49 seconds with O'Callaghan taking silver with 55.62 and American Claire Curzan third.

The triple Olympic gold medallist needed a big finish to overhaul the field.

"I had a rough turn on the third 25 and I had to give it everything cause I had a bit of catching up to do," the 21-year-old said.

Teen Isaac Cooper, who was banished from the Commonwealth Games team for misusing prescription medication, won bronze in the men's 100m backstroke behind American Ryan Murphy.