Pieres began traveling to America to play polo in 1980, when he held an eight-goal handicap.
In 1994 Gonzalo won the Argentine triple crown with Adolfo Cambiaso, Mariano Aguerre, and Carlos Gracida.
For many years Gonzalo played with Kerry Packer,[2] and in 1992 they founded Ellerstina, a polo team that has claimed multiple titles at the Argentine Open and other high-handicap tournaments.
In addition, the Pieres still have strong ties with Packer's son James.
Gonzalo has a daughter, Tatiana who is married to Mariano Aguerre also a 10 goler at Ellerstina on the 2012 season.