I can’t find any video of current Sri Lankan competitors online, though hopefully Christine Merrill will get somewhere in the 400 meters. Once, however, Sri Lanka put on a good show at the Olympics, on par with, like, India. The highlight (in recent memory) was Susanthika Jayasinghe taking bronze in the 200 meters, a premier event. Winner Marion Jones later had her medal pulled due to doping, so Jayasinghe now has a silver. It was a good race, which you can watch above.
Susanthika (or Susan J. Singh, as the announcers called her) placed third in a highly competitive event, and lost ultimately to someone that was doping. So it was a great show, and a big source of pride for Sri Lanka. We haven’t got back there yet, but it’s nice to remember.