Petria Thomas won the 200m butterfly and helped Australia to the 4x100m medley relay to take her gold medal tally to five at the 2002 Commonwealth Games.
Thomas swam the butterfly third leg and gave her team the lead after they were trailing South Africa for most of the race.
It was left to compatriot Jodie Henry to swim the last leg and the 100m freestyle champion made no mistake as Australia recorded a Commonwealth Games record time of four minutes 03.70 seconds.
South Africa's Helene Muller helped her team home in 4:05.06 while England's women touched home in 4:05.65.
Earlier, Thomas began her golden day by winning the 200m butterfly.
After victories in the 50m and 100m butterfly, as well as the 4x100m freestyle, Thomas never looked like throwing away the chance of another title.
"I wouldn't quite call that comfortable," Thomas said. World champion Thomas stamped her authority on the race from the outset and led by a vast 1.5secs at the 100m mark. The 26-year-old was close to world record pace before fading slightly in the closing metres, but victory was never in doubt.
World champion Thomas stamped her authority on the race from the outset and led by a vast 1.5secs at the 100m mark.
The 26-year-old was close to world record pace before fading slightly in the closing metres, but victory was never in doubt.
There was another gold for Australia in the 400m individual medley as Jennifer Reilly led from start to finish to take the title in 4:43.59.
But it was Elizabeth van Welie who put in the performance of the race by collecting silver half an hour after competing in the 200m fly final.
The New Zealander finished just a metre back, with Jessica Abbott of Australia holding off the charge of England's Rebecca Cooke for bronze.
Cooke recovered from seventh at the halfway mark to clock a personal best of 4:47.23, but missed out on a medal by just 0.16secs.