Substitute Luciano Gondou restored Argentina’s lead with a close-range finish before a superb strike by Ezequiel Fernandez six minutes from time secured all three points for the 2004 and 2008 gold medallists.
Spain dominated from the early stages and went ahead in the 24th minute when Fermin Lopez pounced on a poor clearance by the Dominican goalkeeper to score.
Angel Montes de Oca equalised with a towering header from a corner in the 38th minute but Dominica’s hopes of a shock suffered a major blow with Edison Azcona’s red card for a foul on Pau Cubarsi.
Alejandro Baena restored Spain’s lead when his long-range strike deflected off an opponent into the net and Miguel Gutierrez’s tap-in into an empty goal sealed victory.
Hosts France, Israel, Japan and the United States are in action later on Saturday.