What is the round when the match was against sergis kyratzis?
CREATE TABLE table_9621 (
    "Edition" text,
    "Round" text,
    "Date" text,
    "Against" text,
    "Surface" text,
    "Opponent" text,
    "Result" text
)
SELECT "Round" FROM table_9621 WHERE "Opponent" = 'sergis kyratzis'
Below are sql tables schemas paired with instruction that describes a task. Using valid SQLite, write a response that appropriately completes the request for the provided tables. ### Instruction: What is the round when the match was against sergis kyratzis? ### Input: CREATE TABLE table_9621 (
    "Edition" text,
    "Round" text,
    "Date" text,
    "Against" text,
    "Surface" text,
    "Opponent" text,
    "Result" text
) ### Response: SELECT "Round" FROM table_9621 WHERE "Opponent" = 'sergis kyratzis'