Queen of the pool Ellie Simmonds has set up her bid for a second gold - by smashing her own world record.
The teenage star, who has once again been taken to the nation's hearts, started her campaign for the SM6 200m individual medley at the aquatics centre in fine style.
Simmonds, 17, who has dwarfism, will be confident of matching her double gold medal haul at the Beijing Olympics when she lines up later.
She said: "It's quite hard work. There's a lot more pressure on me here. I was going in as world record-holder so I was quite nervous."
Speaking before her heat, Simmonds' father Steve said he was looking forward to the race. He said he enjoyed watching his daughter's races, despite the nail-biting finish to her 400m freestyle win over US swimmer Victoria Arlen.
"I cannot wait. I think she is going to sparkle," he said. "It is a completely different kettle of fish. It is four different strokes and seven people in the water, with people who are good at different strokes that she is not good at. I like seeing her compete."
Lee Pearson will be looking to secure his place in British Paralympic sport's most exclusive club by winning gold at Greenwich Park later.
The 38-year-old from Staffordshire contests the Grade Ib freestyle competition, knowing that victory will put him alongside Tanni Grey-Thompson and swimmer David Roberts on a British record 11 Paralympic golds.
The Olympic stadium was awash with emotion and controversy on Sunday night as a clearly disappointed Oscar Pistorius criticised Brazilian rival Alan Oliveira's "longer" prosthetic legs.
The South African star - nicknamed the Blade Runner - will meet the International Paralympic Committee to discuss the issue.