Haras Las Dos Manos's Latency stamped himself as South America's best horse on Saturday as he swept from far back in the pack to capture the $150,000 Gran Premio Latinoamericano (Uru-I) at Uruguay's Maronas National Racetrack. The win gave Argentina its fourth victory in the international invitational. Latency, a versatile son of Slew Gin Fizz-Latencia, overtook the game Brazilian-bred mare Necessaire, a member of the Uruguayan contingent, in deep stretch and stopped the clock in 2:00.27 for the 2,000 meters. A winner of grade I races at about 1 1/4 miles on turf and dirt, Latency is being compared to Gentlemen, another Argentine who eventually came to the United States for a successful run. In his race prior to the Latinoamericano, Latency scored over the same distance in 1:57.81.Under a heady ride by Uruguayan native Julio Mendez, Latency tracked the pace set by the Peruvian mare Baleriana and Necessaire, then drifted toward the middle of the track for a sustained drive through the 580-yard slightly uphill stretch to prevail by 1 ¾ lengths over Necessaire. Another Argentine, Gal's Honey, finished third, with the Peruvian Baleriana holding off Chilean Super Bull for fourth. Juan Udaondo trains Latency.