(File image) South African swimmer Natalie du Toit

London - Matthew Cowdrey on Thursday picked up the 12th Paralympic career gold medal and his third in London after a virtually sleepless night, as Natalie du Toit won again on the eve of her retirement.

The 24-year-old Gold Coast swimmer became Australia's most-decorated Paralympic athlete on Wednesday, going past athlete Tim Sullivan's previous best of 11.

But Cowdrey said he had under-estimated the effect of the achievement, as he returned to the Aquatics Centre for Friday's heat and final of the men's SM9 200m individual medley.

“That one hurt. I'm not going to lie at all about that,” he told reporters.

“I don't think I fully understood how emotionally and physically draining it was last night and the last couple of days, and being a 10-day (competition) it definitely is a lot bigger and harder than what we're used to.

“I only got a couple of hours' sleep last night. After three or four hours' sleep this afternoon, I would have been ready to come out and go for it tonight.”

Cowdrey's parents flew in to see him race in London courtesy of an undisclosed benefactor.

“They don't usually come over and I've talked about how they've sacrificed to get me here today - and monetarily that's a big one,” he said.

“They probably couldn't have afforded to get over here and they definitely wouldn't have let me pay for it either. For them to step up and do that for me, that's pretty special.”

Natalie Du Toit of South Africa also took her third Games gold as she prepared to bring the curtain down on her glittering career that has not only seen her win 13 Paralympic golds but also compete at the Commonwealth Games and Olympics.

The 28-year-old won the women's SM9 200m individual medal and was roared to the line by the crowd in the 17,500-capacity Aquatics Centre but said she had mixed emotions heading into her final race on Friday, the S9 100m freestyle.

Du Toit is the current world record holder at the event.

“(I'm) sad, relieved and I think scared because I have no idea what I'm going to do but also scared because those girls are swimming well. To walk away with a medal will be very special with it being the last competition,” she said.

“Hopefully afterwards I won't cry, I'm gonna give it everything,” she added but ruled out changing her mind about retirement. - Sapa-AFP