Oscar usually competes in the T forty-four class of disabled athletes.
This is for those runners with both legs removed.
Oscar holds the world record for the one hundred, two hundred and four hundred metres.
In March 2007, Oscar ran in the South African National Championships.
But this time, he competed against runners with whole, healthy legs.
He came second.
A lot of people were surprised - but not Oscar.
He said, "I do not see myself as disabled.
I think it is the person that wants to win the hardest that gets it."
And Oscar wants to win very much.