London 2012 will mark the final chapter for Du Toit, who will bow out of competition after the Paralympics.
The South African had won 10 titles over two Games before competition started in London, with retirement looming for the 28-year-old.
'It's the last time I'll swim the 100m Butterfly, so that's the third race and three golds.
'Tomorrow's the 100m Backstroke, which I think is more of a challenge. I have to concentrate on that one now.'
On retiring, Du Toit added: 'I decided as a little girl that 28 would be old enough and young enough to still know that I've achieved everything possible. But I could also go out there and study, and achieve different things.
'Six, seven, eight hours a day training, it's impossible to study.
'That's one thing on the cards, and work. And just give back in a little way as well.
'I'm going to put it all together in a package and we'll see what happens next year.'
There was a raucous atmosphere inside the Aquatics Centre, which reached a crescendo when Britain's Jonathan Fox won the 100m Backstroke - S7 in 1:10.46 after lowering his own world record in the morning.
There were five world records tonight and seven today in total, including Chinese pair Zheng Tao and Lu Dong in the men's and women's 100m Backstroke - S6 with times of 1:13.56 and 1:24.71 respectively.
Benoit Huot of Canada lowered his own 200m Individual Medley - SM10 record to 2:10.01 as did Daniel Dias in the 50m Freestyle - S5 (32.05).
Sophie Pascoe lowered the 200m Individual Medley - SM10 record she had cut this morning to 2:25.65.
Elsewhere, Sergey Punko successfully defended his 400m Freestyle - S12 title with fellow Russian Oxana Savchenko winning the women's equivalent.
Jessica Long set a Paralympic record of 1:10.32 in the 100m Butterfly - S8, Charles Rozoy of France taking the men's race with Tamas Sors of Hungary winning the S9 event and Du Jianping securing the men's 50m Breaststroke - SB2 crown.
Jacqueline Freney set a Paralympic mark of 1:22.84 in the 100m Backstroke - S7 and Nataliia Prologaieva won the 50m Freestyle - S5.