David Roberts picked up his fourth gold medal of the Athens Paralympics with victory in the S7 50m freestyle final.
The Welshman's victory took Britain's tally of golds to 14, just one short of the 15 they won in Sydney.
His British team-mate Matt Walker led for most of the race but was forced to settle for silver.
There was more British success in the Aquatic Centre with silver medals for Maggie McEleny and Mhairi Love and a bronze for Nyree Lewis.
Roberts had to fight off a determined challenge from Walker to claim gold, following up his victories in the 400m freestyle, 4x100m freestyle relay and the 100m freestyle.
The 24-year-old from Pontypridd clocked 28.77 seconds, edging Walker into silver medal position by just 0.03secs.
McEleny took silver in the women's SM4 150m individual medley as Japan's Mayumi Narita set a new world record.
Love took silver in the women's S6 400m freestyle final behind Mexico's Doramitzi Gonzalez, who broke the world record.
Lewis could only finish third behind Love, despite setting a Paralympic record in the heats.
Darren Leach, Jenny Coughlin, Rhiannon Henry, Claire Cashmore, Graham Edmunds and Sarah Bailey missed out on medals in their finals.
South Africa's Natalie du Toit won her fifth gold medal of the Games with a world record in the women's S9 50m freestyle final, in which Cashmore finished fifth.