Who is iván navarro's opponent?
CREATE TABLE "best_5_matches_by_atp_world_tour_com" (
  "event" real,
  "round" text,
  "surface" text,
  "winner" text,
  "opponent" text,
  "result" text
);
SELECT "opponent" FROM "best_5_matches_by_atp_world_tour_com" WHERE "result"='iván navarro';