Les Bleuets had however taken the score with a penalty from the back Max Auriac in the 4th minute.
In the 27th, hooker Victor Montgaillard was at the conclusion of a one-touch combination in the Irish 22 meters.
With the transformation of Auriac, the lead of the Bleuets increased to ten points, but the Irish found the opening in the 32nd by James McCormick.
At the break, the French led by three points (10-7), a lead increased to six points shortly before the hour mark (16-10).
But a try from center Ben Brownlee in the 79th minute, transformed by Charlie Tector, while the French were outnumbered after a yellow card, turned the tide of the match and gave the siren victory to the young green shoots.
With two victories, the Irish took the lead in the tournament alone.
For the opening of the tournament, on February 4, the U20 tricolors had largely beaten Italy 41-15 while the Irish had swept Wales 53-5.
The third victorious team on the first day, England, title holders of the U20 tournament, suffered a historic defeat in Italy (6-0) after a padlocked match.
The young Italians had never beaten the English in this age category.
Wales beat Scotland (26-13).
© 2022 AFP