Answer
The breakthrough performance that launched Song Hye-kyo's acting career was her portrayal in the renowned South Korean television drama "Autumn in My Heart." This heartwarming series, which aired in 2000, captivated audiences with its poignant story of love, heartbreak, and overcoming adversity. Song Hye-kyo's portrayal of the female protagonist, Yoon Eun-su, brought her widespread recognition and cemented her status as a rising star in the entertainment industry.