In athletics the maximum number of entrants from a single country in most events is three, allowing in theory for athletes from the same country to finish in all three top places.
Carl Lewis has been a part of four American sweeps.
Kenya has swept the 3000 metres steeplechase three times, with Ezekiel Kemboi and Brimin Kipruto a part of two of them.
Sweeps have only occurred eleven times in women's events.
Tirunesh's husband, Sileshi Sihine, was a part of Ethiopia's men's sweep.