The 21-year-old Spaniard, who fought back from a poor start at the new Termas de Rio Hondo circuit, became the first rider in 43 years to win all of the first three races in the premier category from pole position.
The last to be so dominant was Italian great Giacomo Agostini in 1971.
Marquez's Repsol Honda team mate Dani Pedrosa finished second with Yamaha's Jorge Lorenzo taking third place to complete a Spanish sweep of the podium places.
Italian Valentino Rossi, who won the opening three 500cc races of the 2001 season, was fourth.
Marquez now has a maximum 75 points with Pedrosa on 56 and Rossi third on 41.