Du Toit wins first gold for SA at Paralympics
Having breezed through the heats in the morning, she went on to win the final for the third Games in succession, in one minute, 9.30 seconds (1:09.30).
Sarai Gascon of Spain and Elizabeth Stone from America were second and third respectively, in 1:09.79 and 1:10.10, in a closely contested race.
Competing for the last time at a Paralympics, Du Toit said she was feeling more relaxed and determined to just enjoy the experience.
"After everything I've gone through, it's actually quite a relief that it's my last Games," Du Toit said.
"It's a great feeling to be able to walk away and know that I've achieved everything I wanted to achieve and there's nothing else that I could have done.
"So I'm more relieved than anything else."
Five-time gold medal winner at both the Paralympics in Athens and Beijing, Du Toit has kept a low profile in the lead up to the London Games.
"London has been great and I've been able to see a few of the sights which took a bit of the pressure off the racing," she said.
"That was my aim coming into this competition – just to have fun and enjoy what I'm doing."
The 28-year-old from Cape Town, who had her left leg amputated at the knee after she was hit by a car while riding her scooter, will take part in a further six events in London.
Du Toit will be back in the pool on Friday in the 100m backstroke event.
Aiming to go out with a bang, she will also compete in the 100m breaststroke later in the week and attempt to defend her medals in the 50m, 100m and 400m freestyle races and the 200m individual medley.
Sapa's reporter is in London as a guest of the South African Sports Confederation and Olympic Committee – Sapa.