Vlahakis was a professional lacrosse player with the Long Island Lizards of Major League Lacrosse (MLL) and is the holder of four MLL All-Time face-off records. He broke the MLL career face-off wins record with 1,054 and finished No. 2 in career face-off percentage. He still holds the single game face-off wins (35) record and the record for being a four-time defensive player of the week in a single season. Vlahakis was selected to participate in the 2007 and 2008 MLL All-Star Game.

Vlahakis was drafted in the fourth round of the 2004 Major League Lacrosse Collegiate Draft by the New Jersey Pride. On July 3, 2008, he set the league record for face-off wins by winning 35 in a single game.

Vlahakis attended Fairfield University where he won 620 face-offs, which was the fourth-highest in NCAA history. He was a two-time All-New England selection and pre-season All-American in 2002.