Grapefruit and Clementines in Caramel Sauce

Peel clementines and cut into sections. Set aside. Peel grapefruit, removing any white pith. Cut crosswise into rounds about 1/2-inch thick; cut these rounds into halves, then quarters.

Lay grapefruit in overlapping pieces in 8-by-5 heatproof baking dish; scatter clementines atop grapefruit.

DO-AHEAD TIP:
Can be made up to 1 day ahead at this point. Cover and refrigerate.

Stir sugar and 1/2 cup water in heavy large saucepan over medium-high heat until sugar dissolves. Increase heat; boil without stirring until syrup turns deep amber, occasionally brushing down sides of pan with pastry brush dipped into water and swirling pan, about 12 minutes. Cool 30 seconds. Carefully pour in 1/2 cup hot water (mixture may splatter). Return pan to medium heat and stir until blended and any hard caramel dissolves.

DO-AHEAD TIP:
Sauce can be made 2 days ahead at this point. Cover sauce and refrigerate. Stir over low heat to rewarm before serving.

Pour caramel sauce over fruit and serve immediately.