He started playing badminton at aged 7, then in 2004 and 2005 he won the boys' singles and doubles of the Sri Lankan Junior National Badminton Championships.[4][5] In 2007, he won the Jordan Satellite tournament in men's doubles event partnered with Niluka.[6] In 2008, he won his first national senior title in men's doubles event at the Sri Lankan National Badminton Championships. He also won the Uganda International and became the semi-finalist of the Iran Fajr International tournaments in men's doubles event paired with Diluka Karunaratne.[7][8]
In 2011, he became the semi-finalist of Welsh International tournament in men's singles event.[11] In 2012, he won the Sri Lankan National Badminton Championships in men's doubles event and became the runner-up in men's singles event after beat by his own brother Niluka with scores 21-15, 22-20.[12] In September 2012, he competed at the Brazil International tournament in men's doubles event and finished in third place.[13]
In 2013, he won the Uganda International tournament in men's singles event beat Subhankar Dey of India 21-16, 21-17 in a game that lasted 34 minutes. Subhankar took the lead in the two games, but Dinuka's good game reading and clever net play was enough to win him the title.[14] He also became the runner-up of Bahrain International tournament defeated by Sameer Verma of India.[15]
In 2014, he defended his title in men's singles event at the Uganda International tournament after beating South Africa's Jacob Maliekal 2-0 (21-12, 21-15) in a highly supported game and also became the runner-up of the Bahrain International tournaments after defeated by Subhankar Dey of India 21-19, 13-21, 21-11.[16][17] He finished third at the Sri Lanka International tournament after losing a match to Anand Pawar of India in three games, 21-12, 15-21, 21-11.[18] He also competed in the men's singles and mixed team events at the Commonwealth GamesinGlasgow, Scotland, and defeated by Daren Liew of Malaysia 21-19, 21-12 in round of 16. In the mixed team event, the Sri Lankan national badminton team defeated by England national badminton team 3-0, where he played in mixed doubles event partnered with Thilini Hendahewa lose to English paired Chris and Gabby Adcock 21-13, 21-10.[19] In 2016, he became the champion in the men's doubles event at the Uganda International tournament partnered with Niluka, after beat the Egyptian paired Ali Ahmed El Khateeb and Abdelrahman Kashkal 21-17, 21-17.[20]
