Richie Murphy’s side struggled to assert themselves in the opening 40 and left themselves too much to do despite an improved showing after the break.
Aitzol King and Fionn Gibbons impressed once more and both added a score to their U20s tally, but it was not enough as Ireland’s five-game winning run came to an end in Treviso.
France started brightest and came within inches of scoring after a deft chip kick from fly-half Léo Barré. His dink was gobbled up by Emilien Gailleton who almost found the line, as did Samuel M’Foudi a phase later, before full-back Max Auriac kicked the game’s opening points after a scrum penalty.
Ireland’s best moment in the opening quarter came when No.8 Lorcan McLoughlin shrugged off a challenge from M’Foudi to carry his side deep into French territory.
But the Ulster man threw a loose pass which squandered possession and put France back on the front foot.
And they wasted no time in punishing Ireland. Second row Léo Labarthe latched onto an inside pass from Barré and darted home to score under the posts.
Gailleton was never far away from the action and quickly made it two. A sublime pass from Louis Bielle-Biarrey gave Gailleton the freedom of Verona and after a one-two with Nicolas Depoortere he coasted home to score.
Lock M’Foudi was then carded for a needless late hit on Daniel Hawkshaw and France soon faltered with a man down.
His ill-discipline was clearly contagious as a succession of penalties enabled Ireland to work their way upfield.
The biggest cheer of the day then greeted King’s score after 14-man France simply ran out of defensive cover, as Ireland reduced the arrears to 17-7 just before the interval.
Within three minutes of the second period France and Gailleton were again denied a third try courtesy of the TMO.
Then, as Ireland tried to clear their lines, a harsh penalty against James McNabney presented Auriac with the opportunity to extend France’s lead from the tee and it was one which he gobbled up to take the score to 20-7.
The score which put the game beyond doubt soon followed as France dazzled once more. Substitute Gatien Masse stepped in as first receiver and found Depoortere with a simple but highly effective close-range pass.
The centre then raced away before side-stepping Dylan O’Grady to finish.
Auriac added three more to take France to 30, by which point coach Murphy had made wholesale changes and offered minutes to those who are sure to play a big part in Ireland’s remaining fixtures, with a tight turnaround between games.
And the replacement forwards in particular staked a claim for a starting place against next time out, slowly weighing down the French defence before a penalty try, with the score at 30-14 going into the final quarter.
French replacement hooker Victor Montgaillard and centre Gibbons then traded scores before Montgaillard rounded off the scoring in the final minute.
Next up for Ireland is South Africa, who earlier made a winning start with a narrow 30-22 win over England.
FRANCE U-20 – M Auriac; E Randle (G Masse 33), E Gailleton (capt), Nicolas Depoortere, L Bielle-Biarrey; L Barre (M Garcia 60), B Jauneau (S Tarel 59); T Moukoro (P-E Pacheco 46), C Sa (V Montgaillard 56), E Yemsi (R Bellemand 48); S M’Foudi (y/c 22) (M Suta 67), L Labarthe (R Portat 42); N Della Schiava (L Banos 60), M Baudonne, K Tixeront (J Coulon 40)
IRELAND U-20: D O’Grady; A King, F Gibbons, D Hawkshaw (HIA – G Coomber 21 to 31) (R Malone 78), S McCarthy (George Coomber 56); T Butler (S Prendergast 48), E Coughlan (M Moloney 59); O Michel (G Hadden 48), J McCormick (J Hanlon 53), D McSweeney (Kieran Ryan 48); C O’Tighearnaigh (C Irvine 59), A McNamee (D Mangan 59); J McNabney, R Crothers (capt) (R O’Sullivan 56), L McLoughlin (G Shaw 70).
France: Tries: Montgaillard (2), Labarthe, Gailleton, Depoortere. Cons: Auriac (4). Pens: Auriac (3)
Ireland: Tries: King, Penalty Try, Gibbons. Cons: Butler, Prendergast
REF – A Jacobs (SARU)