Paralympic sweetheart Ellie Simmonds smashed her world record to win a second gold medal - declaring "I'm just so chuffed."
This time there were no tears, just a trademark beaming smile. The 17-year-old said: I'm just so pleased - another world record.
"I'm just so chuffed."
It was a case of double delight for ParalympicsGB, as compatriot Natalie Jones touched home to win bronze.
Jones, 27, who has cerebral palsy, said: "I'm delighted to have a medal and can't believe it was so flippin' close."
Simmonds broke her own world record - which she set in the qualifiers - to take gold number two.
The win - which comes just two days after winning gold in the 400m freestyle - makes her the third Paralympian to taste double gold success alongside cyclist Sarah Storey and equestrian Natasha Baker.
Mr Cameron kissed smiling Simmonds on both cheeks and shook her hand as he presented her with the gold medal.
On Tuesday Simmonds, who has dwarfism, will be hoping to make it a stunning hat-trick of golds as she races in the 50m freestyle.
Dressage golden girl Natasha Baker bagged her second gold at Greenwich Park in the Grade II freestyle class with a Paralympic record score.
The win came 48 hours after she was crowned Grade II individual champion - also achieved with a Paralympic record - and it gave Britain's equestrian team a seventh medal of the Games.
There was also success on the track as Mickey Bushell won gold in the wheelchair 100m race in front of an ecstatic capacity crowd in the Olympic Stadium.
Bushell, from Telford, Shropshire, who broke the Paralympic record, said following his win that he "nearly cried" with emotion as he crossed the line.
The 22-year-old was born without seven vertebrae meaning his legs and hips did not develop.
As a child, he walked around on his hands, which helped build his phenomenal upper body strength.
ParalympicsGB's won eight more medals on Monday - three gold, one silver and four bronze - taking the running total for the games to 62, leaving them second in the table.
But there was disappointment again for equestrian star Lee Pearson, who won bronze at Greenwich Park.
Had he won the Grade Ib freestyle competition, the 38-year-old, from Staffordshire, would have joined Tanni Grey-Thompson and swimmer David Roberts with 11 Paralympic golds.
Organisers hailed the "superb" start to the Games, which has now seen 101 Paralympic records in front of packed stadiums and unprecedented TV audiences.
The team is also well ahead of schedule in the quest for 103 medals at the Games, with 61 - including 18 golds - after four and a half days.
ParalympicsGB chef de mission Craig Hunter hailed the "superb start", adding that his athletes are "slightly ahead of our Beijing total (at this point in 2008)".
Channel 4 announced the highest ever TV Paralympics audience for Oscar Pistorius' controversial defeat in sunday's T44 200m final.
A peak of 4.4 million tuned in to watch the 25-year-old South African, who sparked controversy by criticising the length of rival Alan Oliveira's running blades.
Pistorious - nicknamed Blade Runner - contacted Games organisers six weeks ago to raise concerns over the "unfair" advantage of those using longer prosthetics and will meet officials with a view to potentially altering the rules.
Related on HuffPost: