France (12) 25
French flanker Serge Betsen is tackled by Ireland's Simon Easterby
Tries: Clerc (2)
Pens: Elissalde (5)
Ireland (3) 3
The boot of Jean-Baptiste Elissalde and two tries from Vincent Clerc gave hosts France the win they needed to keep their World Cup hopes alive.
Elissalde kicked five penalties before Clerc, the man who broke Irish hearts in the Six Nations, grabbed his brace.
Ronan O'Gara got Ireland's only score with a drop-goal in the first half.
Ireland will now probably have to score four tries and beat Argentina by more than seven points in their final match to reach the quarter-finals.
Given their form in the tournament so far, the odds are on Eddie O'Sullivan's men boarding an early flight home.
That would be a huge disappointment for Ireland, who had envisaged a quarter-final place at least before the tournament but have failed to rediscover the Six Nations form which raised expectations.
They won their opening two matches in France but were well below par and their failure to secure a bonus point for scoring four or more tries in the victory against Georgia could yet prove costly.
Argentina are all but guaranteed to pick a bonus-point win over Namibia on Sunday, which means they would have 14 points to Ireland's nine heading into the final pool match on Sunday, 30 September.
France got the opening score at the Stade de France through a seventh-minute Elissalde penalty, given against the Irish for not retreating the full 10 metres following a previous infringement.
Ireland had an opportunity to restore parity but O'Gara was off-target with a three-pointer of his own four minutes later.
In the 18th minute, Clement Poitrenaud was denied by Shane Horgan's try-saving tackle which required the video official's verdict.
Ireland were adjudged offside in that move, though, and Elissalde knocked over a simple penalty.
Elissalde landed another penalty in the 22nd minute, awarded for Irish hands in the ruck.
Ireland were relying heavily on O'Gara's up-and-unders to advance downfield, although O'Sullivan's men did look considerably more fired up than for their matches against Namibia and Georgia.
Vincent Clerc scores the first of his two tries against Ireland
France number 10 Michalak missed a penalty from halfway in the 36th minute, and moments later O'Gara was successful with a 25-metre drop-goal to reduce the arrears to 9-3.
The last act of the half saw Elissalde boot his fourth penalty of the night to make it 12-3 to the hosts.
Ireland made an encouraging start to the second half but slipped further behind in the 55th minute when Elissalde maintained his 100% record to make it 15-3.
The first try came two minutes later as Michalak put through a kick with the outside of his right boot to the right corner and it fell perfectly for Clerc.
Worse was to follow for the Irish. With Paul O'Connell in the bin, Clerc collected Elissalde's chip and forced his way over for a second score in the corner, the television match official confirming the score.
Ireland were on the receiving end of a battering by now and they were forced to fight hard simply to restrict France's winning margin.
France: Poitrenaud, Clerc, Marty, Traille, Heymans, Michalak, Elissalde, Milloud, Ibanez, De Villiers, Chabal, Thion, Betsen, Dusautoir, Bonnaire.
Replacements: Szarzewski, Poux, Nallet, Nyanga, Beauxis, Jauzion, Rougerie.
Ireland: Dempsey, Horgan, O'Driscoll, D'Arcy, Trimble, O'Gara, Reddan, Horan, Flannery, Hayes, O'Callaghan, O'Connell, Easterby, D. Wallace, Leamy.
Replacements: Sheahan, S. Best, O'Kelly, N. Best, Boss, P. Wallace, Duffy.
Referee: Chris White (Eng)