Place green beans in a large saucepan and cover with water. Place over medium heat and bring to a boil. Reduce the heat to low, cover the pan and simmer until the green beans are tender, about 10 minutes. Drain off the water and set aside.
Melt the butter in a large skillet over medium heat. Stir in the sugar, garlic powder, salt and pepper. Add the tomatoes and cook, stirring occasionally, until the tomatoes are soft. Stir the green beans into the tomatoes and heat for another minute or two, until the beans are heated through. Stir in the basil and serve immediately.