Heat oil in a medium saucepan over medium heat. Add onion and garlic. Cook, stirring frequently, until onion is tender, about 5 minutes.
Add tomatoes and basil. Bring mixture to boil. Reduce heat medium-low, cover and simmer 30 minutes.
Place soup in a blender container and blend until smooth. Pour soup, a little at a time, through a sieve or strainer, back into saucepan. Press pulp through the stainer using the back of a spoon. Only the seeds should remain in the strainer, to be discarded.
Stir in orange juice, sugar, salt and pepper into soup. Heat through.