The Swiss came from behind to beat South Korea 2-1 in their opening fixture of the tournament in Holland and with Brazil and Nigeria drawing 0-0, they find themselves top of Group F.
One of the finds of last season with his 31 appearances for us in all competitions, Reto went close early on but was rocked when Shin Young-Rok opened the scoring for South Korea after 26 minutes.
Reto, 19, made his mark two minutes later with a superb pass to set up Goran Antic's equaliser.
It took just another five minutes for Reto to carve out what turned out to be the winner when his cross from the right was glanced home by Johan Vonlanthen.
Reto is back in action against reigning champions Brazil on Wednesday.
Reto Ziegler set up both goals as Switzerland made the perfect start in the World Youth Championships on Sunday.