Kliment Kolesnikov, Russia's new teenage swimming phenomenon, completed the European Championships 50 and 100 metres backstroke double on Monday less than five weeks after achieving the same feat at the equivalent junior championships.
The 18-year-old, who broke the world record in Saturday's 50m event, smashed his own world junior mark while winning the 100m final in a Russian senior record of 52.53 seconds.
The latest tour de force brought him a third gold medal in four days of competition after he had also been part of Russia's victorious 4x100m freestyle relay quartet.
To complete his stellar day, Kolesnikov swam even faster (52.51) in the lead-off backstroke leg in the mixed 4x100m medley relay, though the time will not count for record purposes, as Russia won silver behind an Adam Peaty-inspired British quartet.
Peaty, world record breaker in the individual 100m breaststroke, Georgia Davies, the 50m backstroke winner, James Guy and Freya Anderson took gold in a European record 3 minutes 40.18 seconds.
It was in Helsinki at the start of July that Kolesnikov properly announced his brilliance with five golds at the European junior championships, but his progression since has been even more spectacular.
Slicing 0.42 seconds off the mark he had set in Sunday's 100m semi-finals, the youngster, who only turned 18 last month, left his more experienced fellow Russian Evgeny Rylov, the world 200m backstroke champion, 0.21 adrift in the final.
On another evening which saw Russia assert their dominance in the pool, taking their table-topping tally of swimming medals to 15, including five golds, Anton Chupkov added the European 200m breaststroke crown to his world title in a European record 2:06.80.
Meanwhile, Charlotte Bonnet and her boyfriend Jeremy Desplanches may have crowned themselves the golden couple of European swimming in the space of 15 minutes.
First, Frenchwoman Bonnet took the 200m freestyle crown in a lifetime best and championship record 1:54.95 before Switzerland's Desplanches felt suitably inspired to win the 200m individual medley in 1:57.04.
"I saw Charlotte win, it gave me wings," said Desplanches.
"We are both winners, both European champions. I watched her race while I was in the call room. It was hard to keep my concentration but it's great."
Bonnet said: "He told me he didn't believe he could win. I was even more moved by seeing him win than for my own gold medal. I'm so proud of him.
"We train together, we live together, we share everything."
After winning the youth Olympics 200m butterfly title eight years ago, Hungary's Boglarka Kapas became a freestyle specialist but admitted that "I kind of get bored so I wanted to try something new again."
So for the past six months, the 25-year-old has trained again for her old event, the 200m fly, and has improved so swiftly that she was able to land the title in 2:07.13, a victory that left her both astonished and delighted.