Domínguez continued to be a fixture in the Atlético Madrid first-team the following season and in August 2010 he started and played the full 90 minutes in the team's UEFA Super Cup win over Inter Milan. He then scored his first senior goal for the club on 19 December, netting the team's second in a 3–0 La Liga win over Málaga. He scored once more for Atlético Madrid as he ended the season with 28 appearances to his name across all competitions. In the 2011–12 campaign, Domínguez was named as the third-captain for the season, behind López and vice-captain Luis Perea. On 10 September, he made his 50th league appearance for Atlético Madrid when he started in a 1–0 loss against Valencia at the Mestalla. Domínguez ultimately featured in 41 matches as the club ended the season in fifth in the league, thereby missing out on a Champions League spot. He enjoyed success in the Europa League, however, coming on as a late substitute for Arda Turan as Atlético Madrid beat fellow Spaniards Athletic Bilbao 3–0 in the final to reclaim their title.