Salih Ucan and Cenk Sahin (twice) got the goals at the Huseyin Avni Aker Stadium to put Feyyaz Ucar’s side top of Group C.
Joining them in that group are Colombia and Australia, who battled to a 1-1 draw at the same stadium that day.
Daniel De Silva is the youngest player at the tournament and put the Socceroos in front in the first half, only for striker Jhon Cordoba to level for Colombia 12 minutes from time.
The South Americans are next up for Turkey on Tuesday, with El Salvador needing to avoid defeat that day against Australia to remain in contention.
Meanwhile in Group D, Dimitrios Kolovos scored in the 89th minute to give Greece all three points against Mexico at Kamil Ocak.
They had led in the first half through Andreas Bouchalakis before Jorge Espericueta equalised for Mexico just before the break.
That puts the Greeks top of the group for the time being with Paraguay and Mali contesting a 1-1 draw.
Greece play Mali next on Tuesday, shortly after Mexico take on Paraguay. Both fixtures will be in Gaziantep.