Score skin of chicken in a few places. Squeeze fresh oranges. Marinate chicken breast in fresh orange juice overnight in refrigerator. Heat BBQ grill, then cook both sides of chicken, turning every 5 minutes, squeezing orange quarters over chicken as you turn. When chicken is done, baste with Lawry's Sweet and sour BBQ sauce and grill 1 minute more on each side, squeezing more orange juice onto chicken as desired.