In 1943, at the age of 16, he was discovered by the goalkeeping coach of Panionios, Giorgos Roussopoulos, who quackly realized his talent and joined the club.

[3] His performances against Denmark at the 1952 Olympics was not to be unnoticed, as the coach of Internazionale, Alfredo Foni, who was on the stadium was impressed and suggested him to sign a professional contract at the Italian club.

He signed a professional contract with Inter and started training with the Italian club, hoping that the administration of Panionios would concent for the transfer.

However his performances didn't remind his previous impressive form that gave him the nickname "the flying goalkeeper" and disappointed he retired from football at the age of only 28.

During the period 1949–1952 Pentzaropoulos played 8 matches, all of which were for the Mediterranean Cup against Egypt (1–3), Italy B (2–3, 0–3), France B (0–1), Syria (8–0) and Turkey (1–2, 3–1, 1–0).

On 15 July 1952, in the match against the Denmark, at the presence of 7,000 people Pentzaropoulos made the greatest game of his career, making a lot of interventions against the hammering shots of the Danish footballers.

Pentzaropoulos died on 27 March 1979, at the age of only 52 from cancer, failing to witness Panionios conquering the Greek Cup, a few months later.