During the 2012–13 season, Martínez led Wigan through their most successful ever FA Cup campaign as they won it for the first time in the club's history. Wigan's previous best result in the competition had been to reach the quarter-finals; Martínez led Wigan to their first Wembley semi-final after a 3–0 away win against Everton in the quarter-final. Wigan faced Millwall in the semi-final on 13 April 2013, and went on to reach their first ever FA Cup Final with a 2–0 win. They played Manchester City on 11 May, and won 1–0 with a goal in the 91st minute from substitute Ben Watson to become the 43rd different club to win the FA Cup.