Brothers Oliver and Sam Hynd gave Great Britain a good start to the evening session at the Aquatics Centre when they claimed silver and bronze medals in the S8 400 metres freestyle.
Sam was the defending champion and world-record holder but it was his younger brother who attacked on the fifth length to pull away with Chinese swimmer Wang Yinan.
The pair fought out a stroke-for-stroke battle but it was the Chinese who just pulled away and despite his best efforts, Hynd could not make any headway with Wang winning in four minutes 27.11 seconds.
Oliver was second in 4mins 27.88secs - a personal best - with Sam third in 4:32.93.
The host nation claimed another medal in the next final when Heather Frederiksen was second in the women's equivalent.
The 26-year-old has been affected by ill-health over the past year which has seen her hospitalised. Her training was subsequently severely affected and she was clearly emotional after the race in which she finished almost nine seconds ahead of third place in 5:00.50.
Jessica Long lowered her own world record from June for a completely dominant victory in 4:42.28.
There was a fourth medal of the night - and third silver - when James Crisp battled his way into second in the final metres in the S9 100m backstroke.
The medals kept coming when Steph Millward picked up another silver in the S9 100m backstroke in 1:11.07 with Amy Marren, just 14, in fifth.
Aaron Moores claimed Britain's fifth silver - and sixth medal - of the night when he was second in the S14 100m backstroke. The 18-year-old is making his Paralympic debut and showed confidence with a strong swim to touch in 1:04.44.