Not alone did hopes of a second successive Grand Slam disappear, but the way the Irish were so totally dominated for most of the second half hardly augurs well for the three remaining games.
At times France were irresistibly good, but at times, Ireland were a fumbling, indecisive shadow of the team which had gone through last season unbeaten.
Only Jamie Heaslip and to a lesser extent Stephen Ferris and Gordon D'Arcy emerged from this defeat with their reputations completely intact. It could be now that Ronan O'Gara will be replaced for Saturday week's clash with England in London by the young pretender, Jonathan Sexton, while O'Gara's half-back partner, Tomas O'Leary, could also be dropped. Even John Hayes, who is set to win his 100th cap against the English, is no longer safe in the starting line-up.
What's more, Rob Kearney will miss out because of a knee injury and Jerry Flannery could be suspended after he was cited for a reckless kick on France's Alexis Palisson.
"The bigger the game, the little things become so important," said coach Declan Kidney. "Passes that don't stick, momentum, staying calm at the right time. That's what pressure is, and we have to learn from that."
There was a moment early in the game when the balance could conceivably have swung towards the green jerseys. The scoreboard hadn't even begun to tick over when D'Arcy's chip over Clement Poitrenaud bounced wickedly out of his path. If the ball had sat up nicely at that stage, the centre would have scored, and who knows?
Then coming up to the interval with Ireland trailing by 17-3, Paul O'Connell spilled a ball close to the French line. If O'Connell had scored, it would have been 17-10 at the changeover, but the chance was lost, and the Irish were forced to endure a punishing second half with David Wallace's try on the only highlight.
For the winners, Imanol Harinordoquy was imperious, Morgan Parra had a fine match and Mathieu Bastareaud built on his performance in Edinburgh with another contribution that mixed the bludgeon and the rapier. Even the notoriously inconsistent Poitrenaud had the wind in his sails, and when that happens, the opposition tends to have a hard day at the office.
As Ireland came to terms with a first defeat in 12 games, and a first Six Nations reversal under Kidney, there was still plenty of optimism from Ferris regarding the upcoming England match. "You're not a bad team overnight, and if we can improve and cut out the silly mistakes, there's no reason why we can't go there and get a win."
There were actually reasons to believe in the first quarter, but when the outstanding Harinordoquy surged powerfully out of defence and when Cian Healy killed the attack with a off-the-ball tackle on Parra, referee Wayne Barnes had no hesitation in sending the Irish prop to the bin. Parra clipped over the straightforward penalty to make it 3-0, and Ireland's troubles were about to start in earnest.
With Tom Court on as a temporary sub for Healy, and with Tommy Bowe packing down as a makeshift flanker, they barely managed to withstand three punishing scrums in their own 22 before the pressure finally told and William Servat burrowed over beside the posts. Parra added the extras to push the lead out to 10-0.
Although O'Gara reduced the gap with a penalty, the French looked like they might cut loose at any time. Bastareaud ran a superb angle only to be scythed down by a wonderful Bowe tackle, but as the play developed, there was a touch of inevitability about the second try when Yannick Jauzion took Francois Trinh-Duc's perfect pass in his stride.
There was further angst when Kearney limped off to a force a restructuring of the back line with Paddy Wallace coming on in the centre, D'Arcy moving to the wing and Keith Earls to full-back. Ireland finished the half pounding away at the French line, but the opportunity for a desperately-needed try was lost when O'Connell knocked on. Trailing by 17-3, the mountain had become higher and steeper.
France had lost none of their momentum after the changeover and coming up to the hour mark, Poitrenaud cut through for the third try after Bastareaud's assist, and then the excellent Parra rubbed salt in some pretty open wounds with a languid drop goal from 40 metres to make it 27-3.
Ferris and O'Driscoll did the spadework for that riposte by Wallace, but well before another Parra penalty and a drop goal by Freddy Michalak had increased the gap, those hopes of back-to-back Grand Slams had evaporated.
Elsewhere, a dramatic injury time try by Shane Williams gave Wales a 31-24 win over Scotland in Cardiff, while England labored to a 17-12 victory against Italy in Rome.
