
Centre-back Gabriel Milito opened the score with a header in the 15th minute and striker Lionel Messi added a second goal with a powerful left-foot shot three minutes before half-time.
The game left a worrying incident as Argentine defender Nicolas Burdisso had to be stretchered off the pitch in the 71st minute. His head collided with that of a rival as both players were trying to head the ball, and Burdisso, of Inter Milan, appeared to lose consciousness.
Last weekend, twice world champion Argentina initiated its route to South Africa with a 2-0 win against Chile, while Venezuela - the traditional Cinderella of South American football - obtained a surprising 1-0 victory away against Ecuador.
On Wednesday, Brazil - the winner of five World Cups - is set to host Ecuador in Rio de Janeiro, while the games Bolivia-Colombia, Paraguay-Uruguay and Chile-Peru will complete the schedule.
In the South American World Cup qualifiers, each of the 10 teams involved play all the others at home and away.
The top four finishers win a place in the World Cup, with the fifth-place team facing a representative of the North, Central American and Caribbean region in a playoff.