Relieved Deschamps delighted with response
Didier Deschamps was a relieved man in the bowels of the stadium afterwards.
Having coped with the pressure of winning a World Cup with home advantage as a player and captain in 1998, Ireland had given him many more grey hairs as he took a step nearer to guiding France to Euro 2016 glory.
"It was a very hard match for us against a team that has physicality and energy as its trademarks," said the man once famously derided by Eric Cantona as "a water-carrier".
"Our players had to match that and they did. But they know about it now; there are sore bodies in the dressing room.
"Maybe it is no harm now that we have another week off," he said of the scheduling that Martin O'Neill so criticised.
Deschamps said his half-time team-talk was one of the strangest he had ever given.
"I had to be calm, because I did not want to cause a panic in the room. But I had to raise my voice too, because what was happening was not us. We were not playing well and I had to get through to some players."
He clearly got through to substitute Kingsley Coman, whose introduction for the second half changed the course of the game.
"I wanted him on because we needed a goal. That was a minimum requirement - one goal in 45 minutes to save ourselves.
"So I put Coman on and took off a defensive player in [N'golo] Kanté. Bringing on Coman allowed me to push [Antoine] Griezmann inside and up towards [Olivier] Giroud too," Deschamps explained.
"Sometimes the manager looks like a fool when he changes things. This was one of the days when he looks like a genius."
Clearly feeling the heat, Deschamps had a go at his critics before they got to him.
"Some will say 'it's only Ireland'. But no game is easy. Of course the penalty was a great boost for them, but they owned the first half. It was played the way Ireland wanted it.
"We did not have any right to qualify for the quarter-finals. We had to earn it and we did. The objective is achieved.
"We reacted well and we played with lots of enthusiasm from then, but we really had to dig deep to get through this situation.
"This team is really bringing a lot of emotion to the crowd and making everybody fall in love with them.
"There's a lot of emotion here in Lyon and we really needed this great support that we had from the fans."
Griezmann revealed that there were harsh words in the France dressing room at half-time.
The Atletico Madrid star said: "We didn't play well in the first half and we said things in the changing room. The coach said things, the players said things. We were playing for France so we had to give everything we had.
"Our fans helped us and we are happy that we managed to get there."
If nerves were frayed on the pitch and in the stands at a packed Stade de Lyon, Griezmann insisted he was not fazed by Ireland's lightning start, simply because he is used to the pressure of dealing with narrow victories.
He said: "For me, it's like this all year round with Atletico. We win matches 1-0 and we are suffering right until the end.
"We were hoping it would be different here with the French team, but it's been a bit similar. We knew it was going to be a complicated game, so we will enjoy it now.
"We are going to look at what we did well and what we did not do well. We are going to keep training to improve."
French midfielder Blaise Matuidi said he was never worried and knew a goal would come.
"We just believed in ourselves and trusted that we could get at least one goal. It was hard for us, but we knew Ireland would be tired."
Giroud was full of praise for the Irish team. "Ireland played very well until the red card - after that it got easier for us," he said.
"They never gave up - we knew they wouldn't. Their supporters were great too. We really respected them."