Courtois made his debut for Atlético in a 4–0 UEFA Europa League victory over Vitória de Guimarães on 25 August, and three days later kept a clean sheet on his La Liga debut, a goalless draw against Osasuna at the Vicente Calderón Stadium. Courtois became first-choice goalkeeper over Sergio Asenjo, keeping four clean sheets in his first six La Liga games. On 26 November 2011, Courtois received his first red card of his professional career after fouling Real Madrid's Karim Benzema for a penalty in the Madrid derby. Cristiano Ronaldo put the penalty past substitute goalkeeper Asenjo as Atlético lost 1–4. Atlético reached the 2012 UEFA Europa League Final, and Courtois kept a clean sheet as the club won 3–0 over fellow Spanish side Athletic Bilbao.