Olympic champion Adam Peaty won his third European title of the week with 50m breaststroke gold in Budapest.
Peaty, who had already won the 100m and mixed 4x100m medley relay events, claimed victory in the shortest-distance breaststroke race in 26.21 seconds.
“I don’t want to sound arrogant, but that was an outstanding swim,” he told BBC Sport.
Britain’s mixed 4x100m freestyle relay team also claimed a dramatic gold.
The quartet of Duncan Scott, Tom Dean, Anna Hopkin and Freya Anderson finished in a new championship record time of three minutes 22.07 secs.
Anderson overtook Italy’s Silvia di Pietro and also held off the charge of a strong Netherlands team in the closing few metres.
“I just wanted to keep the relay success because all of the relay teams with girls in have won gold and I didn’t want to end that statistic,” she said.
Abbie Wood (200m individual medley) and Anna Hopkin (100m freestyle bronze) won their first individual major international medals, while Luke Greenbank secured 200m backstroke silver.
Italian Benedetta Pilato, 16, set a new 50m breaststroke world record of 29.30 secs to qualify quickest for Sunday’s final, where she will be joined by Britain’s Sarah Vasey, who was third fastest.
Wood, 22, finished the 200m individual medley event in 2:10.03, which was just 0.04 seconds behind winner Anastasia Gorbenko of Israel, but ahead of Hungary’s reigning Olympic champion Katinka Hosszu, who was third.
“To be head-to-head with her is a dream and to set a good time and win the medal, I really couldn’t ask for much more,” she said.
Greenbank, who broke the British 200m backstroke record in both the heats and semi-finals, finished just short of another record mark and was pipped to gold by double world champion Evgeny Rylov of Russia.
“It’s hard when you get so close, but if you’d told me I was going to record those times coming into this meet I would have been over the moon,” said the world bronze medallist.
Hopkin, 25, quit the sport when she was 13, but returned when she was 18 in a bid to reach the World University Games and showed her elite potential by helping England win a relay bronze medal at the 2018 Commonwealth Games.
“It means a lot,” she said. “I’ve won a few relay medals here, but everyone wants that individual one for validation and it certainly gives me a lot of confidence that I can take into the summer.”
The 200m freestyle bronze medallist Anderson was fifth in a race won by Dutch swimmer Femke Heemskerk.
Double Olympic medallist James Guy could be another British medal contender on the final night of swimming at the championships after recording 50.96 in the semi-finals of the men’s 100m butterfly.
Other hopes include English Commonwealth champion Ben Proud (50m freestyle), Max Litchfield (400m individual medley) and the men’s 4x100m medley relay team, which will feature Peaty.
Britain top the standings after six days of racing in Budapest with 20 medals – nine gold, seven silver and four bronze.