Greg Diakomihalis was a five-time New York state champion and had a career record of 219-2 in New York State Public High School Athletic Association matches for Hilton High School.

He became the fourth five-time New York state champion, joining Troy Nickerson, Jacori Teemer and Adam Busiello. Nickerson was the New York and National winner of the National Wrestling Hall of Fame's Dave Schultz High School Excellence Award in 2005 while Teemer and Busiello were the New York winners in 2018 and 2019, respectively.

The first wrestler in Section V history to win five state titles, Diakhomihalis was named Most Outstanding Wrestler twice at the New York State Championships.

Older brother, Yianni, was the New York winner of the DSHSEA in 2017 and became the became the fifth wrestler in history to win four NCAA Division I national championships.