They were made by Dmityr Grigorev of Russia in the men's S10 while Summer Mortimer beat her own record set in the morning session in the women's S10.
Hynd would see his team mates collect another four gold medals throughout the day, a total bettered only by Ukraine, who won another six to double their tally.
[4] Further successes in the morning session included Amalie Vinther collecting Denmark's first medal of the Championship, winning the women's 400m freestyle S8.
While there was double Italian success with gold medals for Federico Morlacchi (men's 400m freestyle S9) and Cecilia Camellini (women's 100m backstroke S11).
The host nation picked up their third gold of the tournament when Chantalle Zijderveld broke the European record in the women's 100m Butterfly S8.
Ukraine continued their strong championship with a further gold medal in the morning, a third win for Dmytro Vynohradets who finished the session with the 200m Freestyle S3 title.
In the afternoon session, Russia began with their fourth and final gold of the day when Dimitrii Kokarev broke the world record in the 200m freestyle S2.
Britain finished as the day's most successful country with five golds in total, which also included a new European record for Andrew Mullen in the men's 50m butterfly S5.