Dharmasena came into the international scene in 1994 against South Africa, aged 22. His quickish off spinners, delivered with a slightly unorthodox action, are invariably accurate making him an ideal one-day bowler, especially in Sri Lankan conditions. With time he has also developed into a useful middle order batsman, which has guaranteed him regular place in the Sri Lankan one-day squad. His career came to a standstill after the Oval Test in 1998, when the ICC questioned his bowling action. However, he was cleared to play again by the Sri Lankan cricket board in July 2000. Since then he has frequently played for the one-day team, especially during home matches, but has only played Test cricket sporadically. He retired from competitive cricket in November 2006 to pursue a career in umpiring.