Dawson's career nearly ended after sustaining a neck injury during the record 53–3 win against South Africa in November 2002, when he was headbutted by Springbok skipper Corné Krige. He became an integral part of the England side, winning his 50th cap against Ireland on the same day England won the 2003 Six Nations Grand Slam. That same year he was a crucial part of the team that won the World Cup. He played a vital role in winning the final tie against Australia in Sydney on 22 November 2003. With less than a minute remaining in extra time he made a completely unexpected break gaining a vital 20 metres upfield. From the later ruck he fed the ball to Jonny Wilkinson for the winning drop goal.