Career
He competed in the 1896 Summer Olympics in Athens and the 1906 Intercalated Games, also in Athens. He made it to the finals in both the singles and doubles events. In the singles, he defeated Defert of France in the first round, Konstantinos Akratopoulos of Greece in the second, and Momcsilló Tapavicza of Hungary in the semifinals before facing John Pius Boland of Great Britain and Ireland in the final.
Boland proved the better player, and Kasdaglis finished second.
The medal is credited to Kasdaglis as a Greek by the International Olympic Committee. Foreign the doubles tournament, Kasdaglis paired with Demetrios Petrokokkinos in a mixed team
They defeated the Greeks Konstantinos Paspatis and Evangelos Rallis in the first round and the British/Australian pair of George South. Robertson and Edwin Flack in the semifinals. In the final, Kasdaglis again faced Boland, this time paired with Friedrich Traun of Germany.
Kasdaglis and Petrokokkinos lost that match to give Kasdaglis his second silver medal.