The 18-year-old was pushed to fourth place in her pet event, despite finishing the race with a personal best time of 23.95s.
Earlier, Jayamanne returned a personal best time of 24.01s and finished in fourth place in the heats to qualify for the semi-finals.
In fact, her performance in the semi-final had a great amount of significance as she became the third fastest Sri Lankan junior female athlete behind Damayanthi Darsha and Susanthika Jayasinghe.
Jayamanne also overtook Shelinda Jansen’s timing of 24.07s in the all time 200m list.
Meanwhile, Sri Lanka’s Tharushi Karunaratne failed to qualify for the final of the Women’s 800m when she finished eighth in the semi-finals with a time of 2.17.82s.