Dawson made his debut for Tottenham towards the end of the 2004–05 season in the 2–2 draw at Liverpool on 16 April 2005. Dawson enjoyed a good 2005–06 season, impressing many with his aerial ability and attitude. This in turn led to a contract extension until 2011. This was followed by a call-up to the England squad as a standby player for the 2006 FIFA World Cup. On 5 November 2006, Dawson scored his first goal for Tottenham in their 2–1 win over Chelsea at White Hart Lane. His goal levelled the score at 1–1 after Claude Makélélé's strike, with Aaron Lennon scoring the winner. Dawson first captained the team in the 2006–07 FA Cup quarter-final match away to Chelsea, due to injuries to stand-in captains Robbie Keane and Paul Robinson and the club's regular captain Ledley King. After a season in which he played all but one of Tottenham's 59 matches, he was rewarded with a new five-year contract on 11 May 2007 which would have kept him at the club until 2012. In the 2007–08 season, Dawson scored his first goal in the UEFA Cup home match against the Greek team Anorthosis Famagusta where Tottenham won 6–1. In November 2007, Tottenham went away to West Ham United in the Premier League and drew 1–1, Dawson scored the away goal. During the course of the season, Tottenham reached the 2008 League Cup Final at Wembley Stadium, where they beat Chelsea 2–1 to earn Dawson his first ever silverware, though he missed the final through injury. In October 2008, when Tottenham played away to Stoke, Vedran Ćorluka suffered an injury in the 77th minute. Dawson replaced him only to be sent off in injury time. In March 2009, Tottenham reached the League Cup final again and faced Manchester United. Dawson was available and was selected for the final which ended 0–0 after 90 minutes. However, Tottenham lost 4–1 on penalties. In April 2009, Dawson sustain an injury against Newcastle United which left him out for the rest of the 2008–09 season. The 2009–10 season was to be judged by many as Dawson's finest season in a Spurs shirt to date as he helped the club to a fourth-place finish, their highest league finish for 20 years and qualification for the 2010–11 UEFA Champions League. On 27 January 2010, he signed a new five-year contract with Tottenham, taking him to 2015.