Einemo made his professional MMA debut in the year 2000. He fought for a number of promotions in Finland and the Netherlands, quickly amassing an undefeated record of 4-0. He made his Japanese debut in 2003 for the Shooto promotion in 2003.

Einemo did not compete from 2003-2006 due to complications of contracting a flesh-eating bacterial infection on his left foot following a surgery.^[4] He completely recovered and returned to fighting in early 2006. He experienced his first professional loss in PRIDE Fighting Championships where he lost to Fabricio Werdum by unanimous decision at Pride 31.