[1] Gunasekera was educated at Royal College Colombo where he played in the Royal-Thomian encounter, starting from 1938.

He entered Colombo Law College in 1940, but interrupted his legal studies to join the Ceylon Defence Force as a Second Lieutenant during World War II.

[2] He started playing cricket for the Sinhalese Sports Club under the captaincy of Fredrick C. de Saram.

His highest first-class score was 212 for Ceylon against Madras in the annual Gopalan Trophy match in 1958–59.

[2] His uncle was Dr Churchill Gunasekara, who also captained the Ceylon cricket team.