Wales head coach Wayne Pivac spoke for a nation when he described himself as feeling "numb" as midnight approached in Paris on Saturday.

With 72 minutes gone, Wales led 30-20 and stood on the cusp of a second Grand Slam in three seasons, some transformation for a team who had won only once in last year's competition.

But those aspirations went up in flames in a chaotic finish.

First their discipline deserted them, with Taulupe Faletau and Liam Williams receiving Wales' first yellow cards of the entire Six Nations, reducing them to 13 men.

Then France pounced, scoring first through captain Charles Ollivon, and then deep into added time, Brice Dulin touched down to seal the most dramatic of French victories - and puncture Welsh dreams of a first Grand Slam secured on foreign soil since 1971.

Wales' players fell to the turf in exhausted despair, the silence of an empty Stade de France interrupted by the celebratory howls of their jubilant opponents.

"It's quite a numb feeling really," Pivac said.

"The boys have put in such a fantastic effort. We were down on players at that point. We were quite down on the penalty count at that point, 15-5 I think it was.

"We were on a final warning and we lost two players so it was very difficult to defend at that point, 13 on 14.

"The guys had done tremendously well to hold out the French attempts at the goal line, which were several in the last few minutes.

"But it was just one too many."

That was the overriding feeling for Wales after a thrilling encounter in which they had gone toe to toe with one of the world's most potent attacking teams.

It also felt like a fitting summation of Wales' Championship, which they had started with next to no expectations.

Pivac lost seven of his first 10 Tests in charge last year, with Wales enduring their worst Six Nations since 2007.

It was a surprise, therefore, when they beat Ireland in this year's opening fixture, and even more so when they overcame Scotland a week later.

After a comprehensive win over England and a thrashing of Italy, performances were improving and Wales suddenly found themselves playing for a fifth Grand Slam in 16 years.

They took their game to another level again in Paris, playing with the kind of tempo and attacking fluency that many had hoped for when Wales appointed Pivac.

"It's just desperately frustrating and the players got so close and yet so far," the New Zealander added.

"It's a tough time for them, but we have to be proud of the performance, proud of the effort we put in throughout the Championship."

Pivac was remarkably calm considering the mayhem of which he had just been a part.

But having come so close, it was difficult not wonder what if, what might have been.

"For us to go ahead 27-20 with 20 minutes to go, there was a major point for us," Pivac said.

"We got a fantastic drive going and there was a yellow card and I was expecting a bit more than the yellow card, maybe a penalty try, but it wasn't given.

"That was frustrating because at 34-20 I think it's probably Championship and possibly Grand Slam."

As it was, the chance slipped away - but not all is lost.

When Wales wake up on Sunday morning, bodies aching, emotionally spent, they can at least console themselves with the knowledge they could still win the Six Nations Championship.

France's celebrations were particularly wild because this bonus-point victory kept alive their own hopes of winning the title.

Les Bleus must now beat Scotland in Friday's rearranged final game of the tournament, with a bonus point and a points difference of at least 21 to be crowned champions.

"I hope they don't," Pivac said with a laugh when he was asked about France's chances of pipping Wales to the title.

"Look, it's a tough one. It's a very good French side as you saw today.

"When we got to a position in the game when we should have kicked on, they just kept coming and coming. They've got a lot of big men and they come hard on to the ball.

"Especially at home, they're a quality side and it's going to be a tough ask for Scotland to come here and win the game.

"But we'll be watching eagerly and we'll just wait and see what happens."