On what surface did a score of 4–6 6–3 6–4 occur at the Tournament of Lahore?
CREATE TABLE "singles_titles" (
  "date" text,
  "tournament" text,
  "surface" text,
  "opponent_in_the_final" text,
  "score" text
);
SELECT "surface" FROM "singles_titles" WHERE "tournament"='lahore' AND "score"='4–6 6–3 6–4';