Amasha de Silva gained her first international experience in 2018 at the Junior Asian Championships in Gifu , where she won the silver medal in the 100-meter run in 11.71 s and in the 200 meters in 24.47 s. In addition, she won the bronze medal in the 4 x 400 meter relay in 3: 45.16 minutes. A month later she was eliminated from the U20 World Championships in Tampere, Finland over 100 meters with 11.86 s in the semifinals and could not qualify for the final with the relay. The following year, she won the silver medal over 100 meters behind the Indian Archana Suseentran at the South Asian Games in Kathmandu in 11.82 s and finished sixth in the 200-meter run in 24.54 s. She also won the 4 x 100 meter relay in 44.89 s.
Personal best
100 meters: 11.71 s (+0.7 m / s), June 8, 2018 in Gifu
200 meters: 24.47 s (+0.1 m / s), June 10, 2018 in Gifu