In a small saucepan, heat oil over medium heat. Add garlic; cook and stir 1 minute. Add chili sauce, brown sugar, 1 teaspoon seasoning blend and 1/4 teaspoon cayenne. Bring to a boil; cook and stir for 1 minute. Remove from heat.
In a small bowl, mix mustard, chili powder and remaining seasoning blend and cayenne; rub over chicken. Lightly coat grill rack with cooking oil.
Grill chicken, covered, over medium heat for 4 minutes. Turn; grill 4-6 minutes longer or until a thermometer reads 165°, brushing tops occasionally with chili sauce mixture.