[3] Specialized in the 400 metres, Thilakaratne is the current record holder for 400m event at Asian Athletics Championships.

After seeing his talents, Anura Bandara, then Ambagamuwa Maha Vidyalaya coach, advised him to participate in the 400 metres.

In the same year, Thilakaratne, Damith De Silva, Mahinda Gunawardane, and Suresh Dematapitiya won the 4X400 relay event by beating the Indian team for the first time.

[8] In 1994, he was selected for the South Asian Games trials with a new Sri Lanka record in the 400m, clocking a time of 47.17.

In 1995, he finished the final with a time of 46.21 seconds and won the bronze medal at the 1995 Asian Athletics Championships.

In 1996 he contested in the Atlanta Olympics, where he beat the 400-metre world record holder Michael Johnson of the United States of America, in a preliminary round with a time of 44.78 seconds.

[19] This is the first time in the history of Sri Lanka sports where an Olympic athlete entered the Parliament.