What is the Opponent in the final with an outcome of winner on 14-may-2007?
CREATE TABLE "singles_5_4_1" (
  "outcome" text,
  "date" text,
  "tournament" text,
  "surface" text,
  "opponent_in_the_final" text,
  "score" text
);
SELECT "opponent_in_the_final" FROM "singles_5_4_1" WHERE "outcome"='winner' AND "date"='14-may-2007';