Barcelona’s two-year reign of the Copa del Rey was in jeopardy after it lost to a nine-man Athletic Bilbao 2-1 at a packed San Mames Stadium on Thursday. Athletic played a man down from the 74th minute, and two men down from the 80th because of red cards in a drama-filled first-leg match in the round of 16. Aritz Aduriz scored and set up another goal in the first half for Athletic, and Lionel Messi scored for Barcelona from a free kick early in the second half.