Antonyms for the phrase "made sparks fly" could include words such as calm, placid, tranquil, peaceful, or serene. These opposite words suggest a sense of peacefulness and serenity, rather than the explosive, energetic nature of sparks flying. Other antonyms might include tame, mild, dull, quiet, or still. These descriptive words connote a sense of calmness and stillness, rather than the dynamic movement and excitement of sparks flying. Ultimately, the choice of antonyms will depend on the context in which the phrase is used and the overall tone and mood that the writer or speaker is trying to convey.