However at the start of the 2011 season, Dong-won missed out two matches, due to injury. He made his return from injury on 20 March 2011, in a 3–0 win over Seoul. It wasn't until on 7 May 2011 when he scored his first goal of the season, in a 2–0 win over Suwon Samsung Bluewings. Two weeks later, on 21 May 2011, he scored again, in a 1–0 win over Jeju United. In the summer transfer window, it was reported in the South Korea media that Ji agreed a move to Premier League side Sunderland. Amid to the transfer speculation, Dong-won scored on his last appearance on 11 June 2011, in a 1–1 draw against Incheon United.
In June 2011, Ji agreed a deal to join Sunderland of the English Premier League as a summer transfer after impressing manager Steve Bruce with his performance in the 2011 Asian Cup, in which he scored four goals and provided two assists in six games. He signed a three-year deal for an undisclosed fee (believed to be around £2 million). Upon joining the club, Dong-won was given a number 17 shirt ahead of the new season.
Dong-won made his first appearance for his new club in a 1–1 draw with Arminia Bielefeld in the club's pre-season tour of Germany. He scored his first goal for Sunderland in a pre-season friendly against Darlington. Ji made his league debut for Sunderland on 13 August 2011 coming on for Asamoah Gyan in the 66th minute against Liverpool. Ji scored his first Premier League goal in the 90th minute against Chelsea from a Nicklas Bendtner assist on 10 September 2011, to which Sunderland lost 2–1. Just 12 minutes after coming on as substitute in the second–half against Manchester City on 1 January 2012, Dong-won scored the winning goal in the 90th minutes, in a 1–0 win. However, his first team opportunities at Sunderland was limited, due to his fitness and he appeared invariably as a late substitute. As a result, he played in the reserve side to regain his match fitness. Towards end of the 2011–12 season, Ji's first team opportunities was further limited by new Manager Martin O'Neill. Despite this, Ji went on to make the total of 21 appearances and scoring 2 times in all competitions.
It was announced that Dong-Won was called up to the final squad of the Asian Cup. Dong-Won appeared in every matches in the tournament and scored twice, as setting up a goal, in a 4–1 win over India on 19 January 2011. He then helped the side reach the Asian Cup until their defeat in the semi–final against Japan following a 3–0 in the penalty–shootout. Despite losing in the semi–final, Ji then scored twice for the second time in the tournament, in a 3–2 win over Uzbekistan three days later to earn themselves a bronze medal. At the end of the tournament, Dong-won scored four goals in six games at the 2011 Asian Cup – a return which helped catch Steve Bruce's eye and seal a move to Wearside. By the end of 2011, Dong-won added three more goals, including scoring twice against Lebanon.