4 boneless skinless chicken breast halves (6 ounces each)
In a large resealable plastic bag, combine the vinegar, oil, lemon juice and lemon-pepper; add chicken. Seal bag and turn to coat; refrigerate for 30 minutes.
Drain and discard marinade. Moisten a paper towel with cooking oil; using long-handled tongs, lightly coat the grill rack. Grill, covered, over medium heat or broil 4 in. from the heat for 5-7 minutes on each side or until a thermometer reads 170°.