text: Below is an context that describes a sql query, paired with an question that provides further information. Write an answer that appropriately completes the request.  # noqa: E501
  ### Context:
  CREATE TABLE table_name_23 (opponents VARCHAR, surface VARCHAR, partnering VARCHAR)
  ### Question:
  Who was the opponent on clay surface when partnered with Horacio Zeballos?
  ### Answer:
  SELECT opponents FROM table_name_23 WHERE surface = "clay" AND partnering = "horacio zeballos"