was an Argentine football goalkeeper who played in the Argentine Primera División for 26 seasons and set a record of 765 league and 52 international appearances, totaling 817 games played. Gatti is the player with most appearances in the Argentine league ever.

During his career, Gatti won three Primera División titles, two Copa Libertadores tournaments, and one Intercontinental Cup, all with Boca Juniors, and played professionally until the age of 44.

Gatti, nicknamed El Loco (The Madman) was recognized for his charisma, his innovative playing style for his position and his eccentricity. He developed himself into a goalkeeper who relied on positional play rather than on his reflexes. He would frequently leave the penalty area to function as an additional field player, and join his teammates in defense – and many times in attack. Unlike most goalkeepers of his era, he made extensive use of his feet, head, and chest to control or strike the ball. He was one of the pioneers of the achique, the goalkeeping technique of running out to challenge an oncoming opposing player. He was also notable at facing penalty kicks, saving 26 of them throughout his career, tied for the most ever in Primera División with contemporary goalkeeper Ubaldo Fillol.

Gatti was voted Player of the Year of Argentina in 1982, and was ranked as the third best Argentine goalkeeper of the 20th Century in a poll by the IFFHS.