K League Championship
In the 2007 season, Jung Sung-ryong continued to compete with Shin Hwa-yong and new signing, Kwon Jung-hyuk over the first choice goalkeeper role at Pohang Steelers. He started the season well when he received his first clean sheet in the opening game of the season against Incheon United, as the club beat them 1–0. He missed several matches, due to international commitment and his own injury concern. This also combined him appearing on the substitute bench in a favour of Shin Hwa-yong. Despite suffering from a colon injury during the international break later to the season, Jung Sung-ryong was in goal when he helped the club beat Jeju United 2–1 to reach the final of the Korean FA Cup. In the first round of K League Championship against Gyeongnam on 20 October 2007, he played until the 118th minute when he was substituted for Shin Hwa-yong; which was proved to be decisive, as Pohang Steelers won on penalties after the game was played through 120 minutes. Jung Sung-ryong was the first choice goalkeeper for the next two matches, beating Ulsan Hyundai Horang-i and Suwon Samsung Bluewings to reach the K League Championship Final. Jung Sung-ryong played in both legs against Seongnam Ilhwa Chunma, as the club beat them 4–1 on aggregate to help Pohang Steelers to win 2007 K League championship. However, he played in both legs in Korean FA Cup Final, as the club lost 6–3 on aggragate to Chunnam Dragons as a Korean FA Cup runners-up. Despite this, Jung Sung-ryong went on to make nineteen appearances for Pohang Steelers.