In October 2012, Williams signed a new three-year contract with Swansea. The club's second season in the Premier League saw a ninth-placed finish and a first major trophy win in English football for Williams and Swansea, following a 5–0 win over Bradford City in the 2013 League Cup final on 24 February 2013. After captaining the team during the final at Wembley, Williams lifted the trophy with club captain Garry Monk, who had come on as a second-half substitute.