The victory was Bautista's 16th of the season, four more than Jonathan Rea who sealed the 2019 championship with victory in Race 2 of the last stage in France.
Starting at third on the grid, Rea quickly moved into second place, with Toprak Razgatlioglu also passing Michael van der Mark into third place.
'Spineless' Jonathan Rea 'let us down' - Laverty
Although threatening the Spaniard, the long straights benefited Bautista's Suzuki engine and Rea could not pass him.
With 11 laps to go, Rea made a mistake allowing Bautista to extend his lead to well over a second and this extended to four by the closing stages.
Watch Bautista take victory in Race 1 in Argentina
Over the last three laps the biggest battle on the track was between second and third with Rea just about holding Razgatlioglu off from passing him.
Riders had mixed views about the dusty conditions in San Juan, with five refusing to take part in the race, while Loris Baz was passed unfit after injuring his wrist during his Superpole crash.