Drain the tomatoes in a fine-mesh strainer set over a large bowl. Using your hands, tear the tomatoes open to remove and discard the seeds and fibrous cores, then let the tomatoes drain for 5 minutes. Set aside 3/4 cup of the tomatoes and 2 1/2 cups of the juice separately; discard any extra juice.

Heat 2 tablespoons of oil in a 12-inch skillet over medium heat until the oil is shimmering. Add the onion and cook until softened and lightly browned, 5 to 7 minutes. Stir in the garlic and oregano and cook until fragrant.

Stir in the remaining drained tomatoes and increase the heat to medium-high. Cook, stirring often, until the liquid has evaporated and the tomatoes begin to brown and stick to the pan, 10 to 12 minutes.

Pour in the wine and cook until thick and syrupy, about 1 minute. Stir in the reserved tomato juice, scraping up any browned bits from the bottom of the pan. Bring the mixture to a simmer and cook, stirring occasionally, until the sauce is thickened, 8 to 10 minutes.

Transfer the sauce to a food processor, add the reserved 3/4 cup of tomatoes, and pulse until slightly chunky, about 8 pulses. Return the sauce to the skillet, stir in the basil and the remaining tablespoon of oil, and season with salt, pepper, and sugar to taste.