South Africa fly-half Yaqeen Ahmed slotted eight points as they defended their World Rugby under-20s title by edging France 16-5 in Tbilisi, Georgia, on Saturday.
Ahmed's contributions guided the Junior Boks to a third crown, having beaten New Zealand in last year's decider and the same opponents in 2012.
Les Bleuets' only points came from a Raphael Audebert try just after the break as they failed to secure a fourth success in the annual tournament.
South Africa led 6-0 at the break thanks to penalties from Western Province's Ahmed, as France had a Romeo Bonnard Martin try ruled out by the television match official.
Flanker Audebert crossed six minutes after the break before Bonnard Martin's lock partner Baptiste Veschambre also had a touchdown of his own chalked off by the video referee.
South Africa centre Markus Muller established a six-point cushion by crashing over before 19-year-old Ahmed slotted the conversion and a late penalty seconds before fulltime to make sure of victory.