In 2005, Cole was publicly criticised by Mourinho after scoring the winner against Liverpool for neglecting his defensive duties. Cole responded positively to this and took advantage of injuries to other players to become one of the stars of Chelsea's Premiership title winning team in 2004–05. He also won a starting place in the England team on the left side of midfield, which England had struggled to fill adequately for several years. Cole's form saw him hit a run of goals towards the end of the season, and his goal against Norwich (blasted in from 22 yards off his weaker left foot) was voted in the top ten goals of the 2004–05 Premier League season. Cole scored 10 goals for Chelsea in 2004–05 and ended the season with the first of his two Premier League Champions' medals. He was subsequently named in the PFA's team of the season.

In the first half of the 2005–06 season Cole secured himself in the Chelsea first team line up, ahead of Shaun Wright-Phillips and Damien Duff. Cole also extended his contract with Chelsea for another four seasons. He ended his season by scoring the one of the three goals against Manchester United, which sealed the title for Chelsea.