Christo Popov made it a hat-trick of French victories in the men's singles as Anastasiia Shapovalova became Russia's first singles champion in Lahti.
Christo Popov and Anastasiia Shapovalova justified their billings of top seeds by taking singles titles at the 2020 European Junior Badminton Championships in Lahti, Finland.
Popov emulated his brother, 2017 champion Toma Junior Popov, in winning the men's singles title.
Shapovalova completed her comeback from knee surgery last December with a thrilling victory in the women's singles final.
The wins bode well for their futures in the sport, as 2017 men's world champion Viktor Axelsen and reigning Olympic champion Carolina Marin won European Junior singles titles in 2011, with rising Danish stars Anders Antonsen and Mia Blichfeldt victorious in 2015.
A hat-trick of French men's singles successes - after Toma Junior Popov in 2017 and Arnaud Merkle in 2018 - was guaranteed as last year's junior Worlds runner-up Christo Popov and Yanis Gaudin made it through to the final.
Gaudin had done it the hard way, beating Denmark's second seed Mads Juel Moller in the quarter-finals and then home favourite Joakim Oldorff, seeded three, in the semis.
The final was close at the start, with world junior number one Popov, who had already claimed mixed doubles bronze with Flavie Vallet, leading 8-7.
The Bulgarian-born left-hander went on to dominate after that, winning seven straight points to take the opening game 21-9.
The second game was closer with Gaudin edging into a 16-15 lead.
Both players showed deft touches at the net, but it was Popov - who became the youngest ever French national men's singles champion in February and is already ranked 77 in the world - who brought up championship point at 20-18.
The match ended in agonising fashion for Gaudin as his shot rolled along the top of the net before dropping down on his side.
That gave Popov victory 21-9, 21-18 and he had warm words for his compatriot as they embraced at the net.
He revealed to Badminton Europe, "I told him that he has shown to France and the rest of Europe that he has the level."
The senior ranks now await Popov who added, "It’s the third time we have an all-French final, I think we are both proud of that. He played very well in the second game and pushed me hard. He really deserves this silver medal and I also say congrats to him."
"I am very proud of my achievement as that was my goal for this year. Despite the cancellation of the World Junior Championships, I am very happy to finish my young career with a win." - Christo Popov
The women's singles final ended proceedings in Lahti, and it was certainly a case of saving the best for last.
All four of the day's previous matches had been decided in two games, but this one went all the way.
Anastasiia Shapovalova and Edith Urell had met in last week's team competition with Urell scoring a surprise win in straight games.
And a repeat looked on the cards when the unseeded 17-year-old Swede took the first game 21-14.
But Shapovalova, who underwent knee surgery in December and only returned to action in action in August, came back to take the second 21-18.
Urell led 15-10 in the third game, but the 18-year-old Russian won six consecutive points to move ahead.
It was a nailbiter after that and a fortunate net cord saw the top seed draw level again at 19-19.
Urell then brought up championship point, but Shapovalova saved it with an easy putaway before a barrage of overheads saw her win the next two points to close it out 14-20, 21-18, 22-20, making her Russia's first singles champion in the tournament's 41-year history.
A devastated Urell told Badminton Europe afterwards, "I am very disappointed as I had a lead in the third game and I could not keep it. I think I lost my focus.
"There have been many good things to take from this tournament. It is also difficult to play two categories. I think I played something like 12 matches, so I am really tired."
Fighting back the tears, Shapovalova said she was able to claw her way back in the decider by being able to "relax and enjoy the game".
"It's really an amazing feeling. Edith is a good technical player with good speed. It is so difficult to beat her, so it is a very good feeling." - Anastasiia Shapovalova
The singles loss was Urell's second defeat of the day after she and Gustav Bjorkler went down 21-19, 21-19 in the mixed doubles final to Germany's Matthias Kicklitz and Thuc Phuong Nguyen.
Russia also took the women's doubles thanks to Anastasiia Boiarun and Alena Iakovleva's 21-12, 21-19 win over Nguyen and Leona Michalski.
But they had to settle for two golds with men's top seeds Egor Kholkin and Georgii Lebedev going down 21-15, 22-20 to Denmark's William Kryger Boe and Mads Vestergaard.
Russia finished top of the medals table for the first time with two golds, a silver, and two bronzes.
Denmark were second with two golds - one coming in last week's team competition - and a bronze.
Next were France with a gold, two silvers, and a bronze to leave them just ahead of Germany on one gold, one silver, and two bronze medals.