Peaty gave himself a clean sweep of four gold medals from as many events. Britain was trailing leader Russia by 1.81 seconds after Nicholas Pyle had opened the race, but Peaty's explosive 100 meters turned that deficit into a lead of one second. James Guy and Duncan Scott built on that to beat Russia by 1.59 seconds and set a championship record of 3 minutes, 30.44 seconds.
"The crowd got going and I knew I just had to hold my ground and get it back to these guys," Peaty said. The Olympic 100-meter breaststroke champion returned to form this week after a rare defeat in the 50 breaststroke at the Commonwealth Games four months ago.
But in the Tollcross arena, Peaty approached his best again, peaking by improving his own world record in the 100 breaststroke to 57.10 seconds on Saturday. Benjamin Proud won the 50 free to raise Britain's medal haul to nine golds and 24 in total, equaling its achievement from the European Championships in Berlin four years ago.
However, it left the host nation one gold medal short of Russia's leading tally. Yuliya Efimova won four of her country's 10 golds as she completed a clean sweep of the breaststroke events by winning the 50-meter race, following her victories on the 100 and 200.
Efimova, who is the Olympic silver medalist in 100 and 200, dominated Thursday's final in 29.81 seconds to beat Britain's Imogen Clark by more than a half-second, though the Russian stayed 0.15 short of the championship record she set in the semifinals on Wednesday.
Peaty's and Efimova's four-gold hauls were matched by Sarah Sjostrom, who won all women's races over 50 and 100 meters in butterfly and freestyle. The Olympic champion from Sweden slammed her hand on the water and put a thumb up after winning the 50 fly in 25.16, around seven tenths slower than her own world record time. Like Peaty, Sjostrom won every event she entered.
"Of course I'm very happy with four gold medals but I always want to compare with the times I've done before and I want to keep improving, see faster times on the scoreboard," Sjostrom said. David Verraszto edged Britain's Max Litchfield to claim his third straight European 400 individual medley title after also winning in Berlin in 2014 and London two years ago.
Ecstatic about his win, the Hungarian climbed out of the pool immediately, put three fingers up in the air and ran toward his teammates in the stands to celebrate. In open water swimming, both golds went to the Netherlands as Olympic champions Ferry Weertman and Sharon van Rouwendaal won the 10-kilometer races.
In the men's event, Weertman caught up with leader Kristof Rasovszky on the final meters and beat the Hungarian in a photo finish, resembling Weertman's Olympic triumph over Greece's Spyridon Gianniotis two years ago.
"I came here to win and even though Kristof was way, way ahead of us, I just kept pushing it and pushing it," Weertman said. "And the touch was amazing, so it was great." Van Rouwendaal beat Giulia Gabrielleschi of Italy by 7.3 seconds as she dominated the women's event, a day after landing the 5K title. The rest of the field, led by another Dutch swimmer, Esmee Vermeulen, finished more than 40 seconds off the pace.
Swiss triathlete Nicola Spirig won the women's event for her record sixth individual European title, after sharing the previous best mark with Portugal's Vanessa Fernandes. The Olympic champion from the 2012 London Games was 0.51 seconds off the lead in eighth position after the swimming, but overtook leaders Jess Learmonth of Britain and Cassandre Beaugrand during the 40-kilometer cycling stage.
Building an insurmountable lead in the 10K run, Spirig had time to shake hands with spectators before crossing the finish 33 seconds ahead of Learmonth, who was the defending champion. Beaugrand took bronze.
"It feels amazing," Spirig said. "I think every medal at Europeans or worlds or Olympics is extremely special and you should just enjoy it." It was the first European title since 2015 for the 36-year-old Spirig, who gave birth to her second child last year.
"I always wanted to stop at 30, but now I'm six years past that and I'm still winning and still enjoying it a lot," she said. The men's triathlon race is scheduled for Friday.