The 2008–09 season was the first that Atkinson took charge of UEFA Champions League games. That season he refereed four matches, including FC Zürich against Real Madrid and Inter Milan versus Dynamo Kyiv. In 2010 Atkinson was fourth official to Howard Webb for the Champions League final in Madrid. He issued his first Champions League red card on 5 April 2011, to Cristian Chivu of Inter Milan as they lost 5–2 at home to Schalke.