There were only two women's categories on display on Day 1, yet the Leipzig-born pair managed to top both the podiums.
Carmen was the first of the Brussig sisters to enjoy success after seeing off Lee Kai-Lin of Chinese Taipei to win the -48kg final.
Ramona then followed in her footsteps shortly afterwards against China's Wang Lijing in the -52kg, winning with an ippon to secure a memorable double victory for the Brussig family.
Carmen said: 'I knew in my first fight that today anything is possible. I have beaten the European champion (Victoris Potapopva) and then the world champion (Lee) today.
'I am very happy now, all the pressure is gone. The gold medal is what I still missed in my collection.'
On her relationship with her sister, and the prospect of competing in Rio in four years' time, she added: 'We do everything together.
'We are 35 now, at that age you cannot plan for another four years. We will take it a bit easier now, but of course not quit from one day to the other.
'You never know, I am not going to say it is impossible [to compete in 2016], but I am also not saying that we will be there.'
As well as the Brussig sisters, there were also two men's categories in action in east London.
Ukraine's Davyd Khorava beat Zhao Xu of China to win the men's -66kg, while another Chinese, Li Xiaodong, could not overcome Azerbaijan's Ramin Ibrahimov in the -60kg category.