The former Swansea striker fired home for Fernando Santos' men in extra time, who had already lost talisman Cristiano Ronaldo to injury
Fernando Santos' side sneaked out of their group with three draws and rode their luck in Sunday's final before snatching a victory in dramatic fashion in the second half of extra time.
Inside a buzzing Stade de France, their task was made all the more difficult when star man Cristiano Ronaldo was forced off in the first half , but Portugal dug deep to keep the hosts out despite huge pressure.
Raphael Guerreiro struck the post with a gorgeous free-kick in the additional 30 minutes but Swansea reject Eder was the hero for A Seleccao, rifling home to seal a memorable win against the odds.
Here are five things we learned:
1. Eder is the hero
Eder signed for the Swans for £5m last summer. He left in January after 13 goalless Premier League appearances.
But in the biggest game of his career, he wrote his name into Portuguese folklore.
It was his first competitive goal for his country!
It send the Portugal fans inside the stadium wild and in turn devastated a whole nation.
Simply incredible.
2. Heartbreak for Ronaldo but happy ending arrives
Portugal's talisman was left in serious discomfort after a heavy clash with Dimitri Payet, that ultimately ended his Euros dream.
His reluctance to come off even saw him try and return to the field but after pulling up again, it was obvious his night was over.
It's been 12 years since his first European Championships final ended in heartache and nobody wanted it to end this way - not even the French support inside the Stade de France.
For us watching, the final was a worse place without the Real Madrid superstar. But he still made a difference, giving a teamtalk after the 90 minutes and shouting instructions deep into extra time. It was no surprise to see him leading the celebrations after a night that looked like ending in such a sad way.
3. Payet's night ends early
At that stage he looked a shoo-in for Player of the Tournament, but Antoine Griezmann came to the fore in the first knockout games when France needed some spark.
Payet had his worst game of the summer in the semi-final against Germany, struggling to find space against an organised defence.
L'Equipe awarded him a measly 3/10 for that performance, which was remarkable given his importance to this side.
Always busy on the left, he swapped passes with his midfielders and found pockets of space time and again, while his final ball always caused problems: a cross to Griezmann almost led to the opener and his set pieces were as accurate as ever.
It was odd, then, to see him subbed off before the hour mark and replaced by Kingsley Coman.
It was a harsh end to a fine tournament for the late blooming winger... and meant his final performance will probably be best remembered for the challenge that injured Ronaldo.
4. Sissoko shines again
It appeared Kante would be back in for the semi-final with Germany. He wasn't, and the Leicester man was on the bench again in Paris.
Sissoko has given France a completely different dimension on the right flank and they look a lot more balanced with him in their side.
Sissoko's impact showed when Deschamps opted to bring Payet off to make way for Kingsley Coman.
He very nearly won it too with a fierce long-range strike that was denied by Patricio.
Let's get one thing straight, he won't be a Championship player come August.
5. Portuguese take too many chances
Jose Fonte was the culprit as he tried to play a risky sideways pass that was immediately intercepted.
Fortunately for him, France couldn't make it count but they very nearly did moments later after an error from Fonte's defensive colleague.
This time Pepe was caught dawdling as Payet robbed him of possession before crossing for Griezmann, whose header was tipped over by Patricio.
A let off...and a major warning sign for Portugal.
6. Paris was bouncing
The huge Portuguese community in France – and all those who travelled for this game – were in fine voice in the streets of the capital ahead of kick-off and contributed to a booming atmosphere inside the stadium.Their anthem was impeccable and even competed with La Marseillaise, that eternal call to arms. After the nervousness of France's group games, there was a festive, determined spirit here, with the home fans roaring on their charges.
Just nine months after the tragedy of the Paris attacks, which brought global terror to the front door of the football world, it was good to see supporters enjoying themselves at the Stade de France. This was a day that will live long in the memory for many, many people.
7. The apocalypse may be nigh
Before kick-off, the usual talk of formations and star men was overshadowed by the presence of some unwanted visitors at the Stade de France.Competing for attention with the players were hundreds – maybe even thousands – of MOTHS infesting this grand stadium . They certainly got on the nerves of Pierluigi Collina and Mark Clattenburg before kick-off.
