The Frenchman had to battle past Jimmy Vicaut to cross the line first in a time of 10.09, 0.03s quicker than his second-placed compatriot.
Norway's Jaysuma Saidy Ndure claimed bronze with a time of 10.17, beating Britain's Harry Aikines-Aryeetey into a creditable fourth place.
Serhiy Smelyk of Ukraine finished fifth, but also in last place after the final was finally completed at the third time of asking.
Lithuania's Rytis Sakalauskas, who picked up an injury in the semi-final, stayed in his blocks when the gun first went off, and was shown a yellow card. At the restart Sakalauskas again barely managed to leave his starting position, only this time Italy's Simone Collio had clearly false-started and was immediately disqualified.
When the final did eventually get underway, Sakalauskas once more took himself out of the race, while Latvia's Ronalds Arajs pulled up midway down the track.
"I am massively upset," Aikines-Aryeetey admitted after missing out on a medal.
"This year has just been terrible to me after last year being so good.
"At the start of the year nothing went right for me. As much as I wanted it, as much as I tried to do everything I could, nothing went my way.
"Even going to the Olympic Stadium for the test event, I tore a muscle walking - how unlucky can you get?"
Ivet Lalova was the surprise winner of the women's 100 metres title earlier in the afternoon session.
The Bulgarian powered past narrow favourite Olesya Povh of Ukraine in the final third of the sprint to take the gold in a time of 11.28 seconds.
Povh crossed the line in second 0.04s after Lalova, while bronze went to Lina Grincikaite. The Lithuanian also clocked a time of 11.32, a season's best for her.
Defending champion Verena Sailer could only muster sixth place as the best performing of the three Germans in the final.
There was better news for Germany in the decathlon, which Pascal Behrenbruch won convincingly with a total of 8558 points, 237 ahead of silver medallist Oleksiy Kasyanov of Ukraine. Russia's Ilya Shkurenyov was third, while Briton Ashley Bryant's excellent performance in the javelin helped him to a 12th-place finish.
The main javelin event was the final event of the day, scheduled as such due to its popularity in Finland, and the home crowd were not disappointed. Finn Ari Mannio claimed a bronze medal with a throw of 82.63 metres, with the gold going to Vitezslav Vesely. The Czech athlete, who is trained by legendary thrower Jan Zelezny, won the competition with a best distance of 83.72, beating Russia's Valeriy Iordan into second place.
The gold in the women's 5000 metres went to Russia's Olga Golovkina who, along with Ukraine's Lyudmyla Kovalenko, beat leader Sara Moreira in the final straight to condemn the Portuguese to a second consecutive European bronze in the distance. Britain's Julia Bleasdale came fourth with a personal best of 15:12.77. Bleasdale's Olympic fate is now in the hands of the selectors.
"It will be a nervous few days and we will have to wait and see," she said.
"I gave it my all but I've got to learn to be a bit more patient."
France's Eloyse Lesueur won the women's long jump with a season-best of 6.81, while Spain's Ruth Beitia won the high jump after matching Tonje Angelsen's 1.97 and the Norwegian was left to count the cost of an error in attempting 1.89.
There will be two British runners in the women's 800 metre final after Lynsey Sharp and Jemma Simpson both qualified from their semi-finals, the latter as a fastest loser. It may well have been a trio of Brits, were it not for Jenny Meadows having to withdraw after her troublesome Achilles swelled up on the flight over.