Brush both sides of fish using 1 tablespoon oil. Season with 1/2 teaspoon salt and 1/8 teaspoon pepper.
Rub cut sides of bread with garlic. Brush with remaining oil, and sprinkle with remaining salt and pepper.
Heat a grill pan over medium-high heat. Coat with cooking spray. Grill bread until crisp, about 1 minute per side. Grill sardines until cooked through, about 2 minutes per side. Serve on a platter with bread and lemon wedges.