With the score of 6–3, 2–6, [10–8] and played on clay who was the opponent?
CREATE TABLE "doubles_6_5_titles_1_runner_up" (
  "outcome" text,
  "date" text,
  "tournament" text,
  "surface" text,
  "partner" text,
  "opponent" text,
  "score" text
);
SELECT "opponent" FROM "doubles_6_5_titles_1_runner_up" WHERE "surface"='clay' AND "score"='6–3, 2–6, [10–8]';