Career
He is a 6"5" (196 m) tall shooting guard-small forward. In the prime of his career, he possessed great scoring ability. In the 2001-2002 season, Diamantopoulos led the Saporta Cup in scoring.
In the 2002-2003 season, he was the Greek League Top Scorer, while playing for Panionios.
He has also been a player of the Greek League clubs Papagou and Olympiacos Piraeus. He then played with the National Basketball Association Summer League squad of the National Basketball Association club the Indiana Pacers.
He joined Maroussi for the 2008-2009 season. He moved to the Cypriot League club Achilleas in 2010, and then to the Swiss League Vacallo Basket in 2012.
He also played with the Cypriot club Keravnos in 2012.
He joined Doxa Lefkadas in 2013. He returned to Panionios in 2014. In 2015, he moved to Papagou.
With Greece"s junior team he also played at the 1999 International Basketball Federation Under-19 World Championship.
1998 International Basketball Federation Europe Under-18 Championship: 03 !.