Cahill scored on his first appearance of the season in a 4–2 win against Reading on 22 August 2012. On 31 August, he scored in the 2012 UEFA Super Cup against Atlético Madrid, which Chelsea lost 4–1. On 5 December 2012, Cahill scored his first UEFA Champions League goal, coming against Nordsjælland in a 6–1 home rout. On 16 December 2012, Cahill was sent-off against Corinthians in Chelsea's 1–0 2012 FIFA Club World Cup Final defeat after a clash with Emerson. In January 2013, Cahill did not feature in the league match against Stoke City due to the birth of his son, Leo. On 15 May, he started the 2013 UEFA Europa League Final against Benfica and made a vital last-ditch tackle in the final moments to ensure that Chelsea won the match 2–1.