A promising career with the national team looked certain when Dammika Prasad took two wickets in as many balls in his first over of his ODI debut against Bangladesh in 2006. He went on to play two more matches before his career was cut short by a back injury which kept him out of the game for six months. Having recovered, he was selected for the Sri Lanka A tour to England in 2007 where he hoped to perform well and regain his place in the national team. What may have helped him in this quest was his ability to bowl at the death in ODIs, having worked hard to develop subtle variations including a good yorker. Consistent performances on the domestic front earned him a first Test cap against India in August 2008 as Sri Lanka sought to add pace to their attack. He did not disappoint, taking five wickets in the match, including the wicket of India's best batsman, Virender Sehwag, in both innings.

Interestingly, Prasad started his cricket at De Mazenod College, Kandana, as a No.3 batsman. He played in this position till he reached 17 when he was forced to switch over to bowling fast because the school could not find anyone suitable to bowl with the new ball. He was selected for the Under-19 World Cup in 2002 and his performance paid off when he won a six-month scholarship to play in England. Prasad's best bowling effort was in the now-defunct provincial tournament when he took six wickets for 25 (match bag ten wickets) for Southern Province against Uva Province at the Galle International Stadium in 2004.