Jonathan Sexton went off injured in the first-half
Ireland dodged a Rugby World Cup quarter-final clash with the All Blacks but their decisive 24-9 victory over France came at a cost.
Second-half tries for Rob Kearney and Conor Murray made it four wins from four in Pool D, setting up a last-eight clash with Argentina and teeing up Les Bleus to face the reigning world champions - and the British & Irish Lions' 2017 hosts - instead.
However, Joe Schmidt could be without a handful of key men for that match after Peter O'Mahony and British & Irish Lions duo Jonathan Sexton and Paul O'Connell were all forced off injured in the Welsh capital.
With a sea of green sweeping across the Millennium Stadium and the sheer volume of the Irish anthem, it would have been easy to mistake Cardiff for Dublin and the atmosphere may have taken its toll on Frederic Michalak, who miscued an early penalty.
But Les Bleus had undoubtedly started the brighter and when Cian Healy was off his feet near the halfway line, Scott Spedding took over the kicking duties - only to see his effort bounce back off the upright.
Sexton made no such mistake with his first effort from the tee, however, and fired Ireland ahead from 40 metres out after Mathieu Bastareaud was caught offside.
Spedding levelled things up from just inside the Irish half, while Sexton hit the post with a drop-goal, but Ireland already had the penalty advantage and their fly-half restored the lead after 19 minutes.
An O'Mahony high tackle prompted Spedding to point at the posts again - this time from inside his own half - and the French full-back made it 6-6 in impressive fashion.
Ireland suffered a significant setback when Sexton hobbled off after 25 minutes but his replacement, Ian Madigan, immediately added some dynamism to the Irish backline before an early Pascal Pape tackle allowed him to restore the Irish lead with his first penalty.
The standout chance of the half arrived on 31 minutes when Tommy Bowe strode clear and fed fellow Lion Keith Earls on his shoulder, but the outside centre fumbled and the opening disappeared.
And the opening 40 ended with worrying signs for Schmidt, as O'Connell left the field in pain to a standing ovation.
The Irish captain did not return for the second half - Iain Henderson emerged in his place - while a Sean O'Brien knock-on halted an ominous overlap on the left two minutes later.
However, Robbie Henshaw had the crowd back on its feet with a break deep into opposition territory and that elusive try arrived after 50 minutes.
A series of pick-and-gos on the French line brought no reward but when the ball went right, Kearney evaded a tackle to reach for the line, though Madigan missed the conversion.
Injury struck again for Ireland, as O'Mahony was taken off on a stretcher, and - with 15 minutes left - Morgan Parra reduced the gap to five after O'Brien failed to roll away.
But it was the men in green who struck next, Rory Best halted inches shy of the line and British & Irish Lions scrum-half Murray reacting quickest to slip over under the posts, Madigan converting.
A collapsed scrum allowed Madigan to increase the lead to 15 with just four minutes left on the clock and that was the way it stayed.