Dimitri Payet capped his man-of-the-match performance with a stunning 89th-minute winner to lift hosts France 2-1 past Romania in the Euro 2016 opener.
The lively West Ham forward smashed the ball into the top left corner from 20 metres to spare Les Bleus blushes in the Stade de France packed with 75,115 fans.
Olivier Giroud had headed France ahead in the 57th off Payet's corner kick, but Bogdan Stancu converted a penalty seven minutes later fro the stubborn Romanians.
Antoine Griezmann was earlier denied by the post for the French but Stancu had also blown a major chance at the start of each half on the other end.
France are bidding to win a third straight big home event after Euro 1984 and the 1998 World Cup, and got an early lead in Group A ahead of their other games against Albania and Switzerland.
Didier Deschamps' team dominated but the defence looked shaky at times and the high-class attack didn't make more out of the chances they got - almost all set up by Payet - against a Romanian defence which had let in just two goals in their 10 qualifiers.
"The result matters most. Not everything was perfect, far from it. But the victory is positive and its very important to begin with a victory," Deschamps said.
"In had no doubts over Dimitiri Payet that he can make the difference," he added. "It was a wonderful goal."
Payet said: "There was a lot of stress and pressue. If someone would have told me I wouldn't have believed it. It all come out with the goal."
The opening game was preceded by a short and vibrant opening ceremony for the 24-team tournament until July 10, featuring cancan dancers and DJ David Guetta.
Security was tight at the vast arena which had been one of the targets during the terror attacks in Paris on November 13, 2015.
The predominantly French crowd appeared to chant their anthem with some extra defiance before kick-off but then quickly held its breath as the high pressing Romanians almost spoilt the party.
Stancu's point-blank range effort at the far right post was somehow kept out by Hugo Lloris, and second later Florin Andone's header sailed just over the bar.
Arsenal's Giroud had a first chance before Atletico Madrid's Griezmann, under pressure from Napoli defender and Romania captain Vlad Chiriches, was denied by the right post in the 14th.
Griezmann's shot off Payet's low cross was slightly deflected to fly inches right, and Giroud then headed high in stoppage time.
Like in the first half, the French were almost caught out cold by Stancu early in the second. Steaua's Nicolae Stanciu found the completely unmarked Genclerberiligi forward in the area but he volleyed wide after trying to control the ball with his chest.
That woke up Les Bleus again, and goalkeeper Ciprian Tatarusanu made a fantastic save with his feet to thwart Paul Pogba's low drive.
But the Fiorentina keeper didn't look good on the ensuing corner which Payet whipped to the far left post where Giroud beat Tatarusanu with a header for an overall deserved French 1-0 lead in the 57th.
The joy however lasted a mere seven minutes. Patrice Evra slightly tripped Staciu and Stancu finally found the net on his third big chance, calmly slotting the penalty into the bottom right corner for 1-1 as Lloris went the other way.
Deschamps brought on youngsters Kingsley Coman and Anthony Martial for Griezmann and Pogba but the game seemed heading towards a draw before Payet came to the rescue to crown his own performance and give France the perfect start they wanted.
"It hurts to lose in the 89th minute - but it was a fabulous strike from a wonderful player," Romania coach Anghel Iordanescu said.