Great Britain's Daryll Neita won bronze as Dina Asher-Smith pulled up with cramp in the European women's 100m, after Olympic champion Lamont Marcell Jacobs won the men's race in Munich.
A three-time European gold medallist in 2018, Asher-Smith slowed after 60m because of cramp in both her calves.
Italy's Jacobs ran 9.95 seconds to beat British defending champion Zharnel Hughes (9.99) to the men's title.
Team-mate Jeremiah Azu ran a personal best 10.13 to take bronze.
Neita clocked 11.00 as Germany's Gina Luckenkemper (10.99) delivered a hugely popular home victory ahead of Switzerland's Mujinga Kambundji in a photo finish.
Earlier, Briton Jacob Fincham-Dukes thought he had clinched his first major championship medal with silver in the men's long jump at the Olympiastadion.
However, an appeal found the 25-year-old's season-best opening leap of 8.06m was a foul and he was demoted to fifth based on his next-best jump of 7.97m
In two thrilling 100m races, Israel Olatunde - the first Irish athlete to reach the European 100m final - set a national record of 10.17 to place sixth ahead of Britain's Reece Prescod, who finished fourth in 2018.
In the women's event, Imani Lansiquot was fifth in 11.21, with Asher-Smith eventually jogging across the line.
Asher-Smith confirms cramp to blame as Neita medals
Asher-Smith entered the championship bidding to defend the three titles she won in 2018 in the 100m, 200m and 4x100m relay.
The 26-year-old was forced to withdraw from the Commonwealth Games after pulling up with a hamstring strain while competing for Great Britain in the women's 4x100m relay final at the World Championships in July.
By then, she had equalled her British record to take an agonising fourth in the 100m in Eugene - missing out on a medal by just 0.02 seconds - before winning 200m bronze.
That success, after which she revealed she had been struggling away from the track following the death of her grandmother, marked her return to a major championship podium after her Olympics campaign was wrecked by a hamstring injury.
There was to be no repeat in Munich - though it appears the problem she suffered was not a serious one.
"I got cramp in my calves and I can't be running on two cramping calves," Asher-Smith told BBC Sport.
"I'll go back and have a chat about my recovery and how I'm hydrating. I feel good which is why I'm frustrated.
"I wasn't about to go and run a whole race on two cramping calves and possibly tear them. Frustrated, it's just very annoying."
Meanwhile, team-mate Neita, who successfully added to her Commonwealth bronze, lost out in a tight finish and also said she had been suffering with cramp.
"I was cramping up a lot. I haven't cramped all year. I was saying a prayer on the start line that I got through in one piece," Neita said.
"I honestly wasn't going to race but who is going to believe me if I said I was cramping up before. I got a medal somehow."
Jacobs adds European title to medal haul
A shock winner as he claimed gold at Tokyo 2020 in a European record time, Jacobs now has his first European 100m title - having become the first reigning Olympic 100m champion to win the world indoor 60m title back in March.
Despite physical problems and illness disrupting much of his outdoor season to this point, the 27-year-old had too much for 2018 champion Hughes.
The former long jumper withdrew from the men's 100m semi-finals at the World Championships last month due to injury, but he moved clear of the field to take gold in a championship record time.
Hughes had to settle for Commonwealth silver in the 200m - qualifying for which begins on Thursday in Munich - before helping England to 4x100m gold in Birmingham.
"I'm happy. It's been a tough season. I'm proud of myself and I'm proud of the team. I wanted the gold medal but Jacobs was just better than me tonight," Hughes said.
"I'm very happy and I'm looking forward to the 200m because that is my favourite event."
Bronze medallist Azu, who won the British title ahead of Hughes earlier this year, said: "I saw first [place] come up, I saw second come up. When I saw my name, I just screamed.
"I have come away with a bronze medal, I ran a PB. People back home know how much of a struggle it has been, there's a lot of things going on behind the scenes but I came away with the medal and I'm grateful."
Disappointment for Fincham-Dukes as silver taken away
Greece's Olympic champion and world silver medallist Miltiadis Tentoglou jumped 8.52m to defend his European title by a commanding margin.
But behind him, three athletes all recorded the same mark of 8.06m, with Britain's Fincham-Dukes placed ahead of Sweden's Thobias Montler and France's Jules Pommery by virtue of his next-best effort.
It stood as Fincham-Duke's best ever outdoor jump and came after he had produced a season's best of 7.86m in qualifying.
However, that medal-winning first attempt was later challenged and a referee decision declared it was a failure, promoting Montler to silver and Pommery to bronze.
Great Britain and Northern Ireland appealed against the verdict but the decision was upheld.
Compatriot Reynold Banigo jumped 7.6m to finish seventh in the final.
In the women's discus final, Jade Lally finished ninth as Croatia's Sandra Perkovic claimed an unprecedented sixth successive title.
Elsewhere, Norway's Jakob Ingebrigtsen, 21, defended his men's 5,000m title as he moved clear of Spain's Mohamed Katir in the final 100m to take gold.
Andrew Butchart was the first Briton over the line, finishing seventh in 13:31.47, ahead of ninth-placed Sam Atkin (13:32.35) and Patrick Dever, who finished 21st (13:45.89).
Laura Muir began the defence of her European 1500m title in style as she breezed into Friday's final by winning her heat during Tuesday's early session.
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