Grigelis holds the best Association of Tennis Professionals doubles ranking for Lithuanian player of all time. Since the end of 2010 Grigelis is couched by Giuseppe Menga. Singles: (10–3) Doubles: (12–8) The table is current through season 2014.
Grigelis won his first title when he was 18 at a Futures tournament in Wrexham, United Kingdom. On Association of Tennis Professionals Challenger Tour Grigelis has won six titles, one singles and five doubles. He won his only singles title in summer 2011 in Aptos, United States. In 2012, Grigelis won five doubles titles. He captured three titles with Uladzimir Ignatik in Wofsburg, Germany, Cherbourg, and Saint Rémy, France, he achieved one title with Rameez Junaid in Saint–Brieuc, France, and one title with Alessandro Motti in Naples, Italy. Grigelis is a member of the Lithuania team, having posted a 6–9 record in singles and a 5–3 record in doubles in twelve ties played.
