PREPARE dressing as directed on envelope. Remove 1/4 cup dressing. Refrigerate for later use. Pour remaining dressing over chicken in shallow dish; stir gently. Refrigerate 30 min. to marinate.
HEAT oven to 450ºF. Drain chicken; discard marinade. Cook and stir chicken in 2 Tbsp. of the reserved dressing in skillet on medium-high heat 8 to 10 min. or until done. Brush remaining dressing onto pizza crust; top with tomatoes, basil, chicken and cheese.
BAKE 8 min. or until cheese is melted and pizza is heated through.