1. Preheat oven to 425 degrees, with rack in top third. Line a rimmed baking sheet with aluminum foil; set aside.

2. Make glaze: In a large skillet, combine juices, rosemary, garlic, and a pinch each of salt and pepper. Boil over high heat until reduced to 1/2 cup, about 15 minutes, stirring and scraping down sides of skillet with a wooden spoon or heatproof spatula. Strain through a fine-mesh sieve into a liquid-measuring cup; stir in vinegar. Reserve cup glaze for serving.

3. Meanwhile, season chicken with salt and pepper. Place, skin side up, on prepared baking sheet; bake 15 minutes, then brush chicken with glaze. Continue baking, brushing with glaze every 5 minutes, until chicken is cooked through, 15 to 20 minutes (an instant-read thermometer inserted in the thickest part, avoiding bone, should register 165 degrees). Let rest 5 minutes; drizzle with reserved glaze. Serve.