Alex Cuthbert's devastating first-half try appeared to have set a rampant Wales up for a straightforward march to victory.
But France hit back hard in the second half to close the gap to within four points before Leigh Halfpenny's late penalty earned Warren Gatland a second Grand Slam at the helm.
The late effort by Les Bleus kept the crowd waiting before they could stop holding their collective breath, but Wales, dominant throughtout the match, were by far the better side on the day as they earned a thoroughly well-deserved fifth win in the championship.
The Welsh passion to win the Grand Slam was evident from the off as the match began at a furious pace.
Within two minutes a blistering break up the left masterminded by Jonathan Davies put the home side on the front foot, but the France defence stood up to the probing by the hosts.
The furious Welsh attacks continued, however, France fly-half Lionel Beauxis kicking for territory at almost every opportunity rather than trying to start an attack.
Yet it was the French who opened the scoring as Mike Phillips undermined a brilliant quick free-kick that he'd tapped and run by hanging onto the ball after being tackled.
From the lineout Wales conceded a penalty which Dmitri Yachvili landed from almost point-blank range on 11 minutes to put the visitors ahead against the run of play.
Yachvili then conceded a penalty almost immediately to give still-surging Wales a chance to draw level, but Rhys Priestland's solid attempt ricocheted back off the right upright.
And France nearly stretched their lead half-way through the opening period as a well-worked short line-out saw David Attoub cut Wales open, but at the subsequent ruck 5m out they went in off their feet.
Within two minutes Wales scored at the other end of the pitch, with Dan Lydiate's crunching tackle on on Thierry Dusautoir seeing the Frence star spill the ball to Priestland. The fly-half whipped it out to Cuthbert, who did brilliantly to break two tackles then avoid a third by cutting inside to score.
With 17 minutes left of the half Wales looked like pulling clear, but they were restricted to just one more penalty 10 minutes later, Alexis Palisson being caught in possession deep in the France 22m after a great chase by the excellent Jonathan Davies.
The crackling pace of the match continued as the second half got under way, with France replacement full back Jean-marcellin Buttin - superb on his debut - whose chip through put Gethin Jenkins under such pressure that he conceded a penalty that was knocked over by Beauxis to make it 10-6 just five minutes into the second half..
Beauxis almost cut the deficit to just one point with a drop goal that went close immediately after the restart, but after a breathless series of turnovers Leigh Halfpenny restored the advantage with a miraculous penalty from inside his own half that soared through the middle of the posts with power to spare.
Wales continued to push forward trying to break the French defence, but the visitors withheld all the hosts' efforts - and as the match entered its final quarter, they looked increasingly likely to spoil the party in Cardiff.
But the mistakes which characterised much of their campaign continued to undermine them: an early push turned a scrum deep in the Wales 22m into a free kick to the defending side, and later Imanol Harinordoquy hung onto the ball after being tackled 5m from the line.
Wales leaked one more penalty, wheeling a France scrum in front of their posts - but with six minutes left they seemed happy to concede three points rather than risk seven.
And France's gamble not to go for another scrum backfired, Wales quickly regaining the ball at the restart before a chip-through by Roberts put Francois Trinh-Duc under pressure. The France sub, flustered as he was tackled into touch, threw the ball away to deny Wales the chance of a quick throw.
The resulting penalty put Wales four points clear with three minutes left, and Gatland's men hung onto the ball thereafter as they ran down the clock with the same brilliant ruthlessness that saw them come through a string of hard-fought matches on the way to their Grand Slam title.
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