SELECT "Score in the final" FROM table_45728 WHERE "Surface" = 'hard' AND "Date" = 'august 20, 1989'
Which Score in the final has a Surface of hard on august 20, 1989?
CREATE TABLE table_45728 (
    "Outcome" text,
    "Date" text,
    "Tournament" text,
    "Surface" text,
    "Partner" text,
    "Opponents in the final" text,
    "Score in the final" text
)