Under his rein, on 23 December 2021, an extremely depleted due to COVID-19 Real Madrid squad won against highly favored CSKA Moscow.

[3] Mateo also led Madrid to a 3–1 victory in the 2022 ACB playoff final series against Barcelona to win a record 36th league title for Los Blancos.

[4] On 5 July 2022, Mateo was promoted to a permanent head coach role after Real Madrid parted ways with Laso.

[5][6] On 21 May 2023, in his first full season as head coach, Mateo led Madrid to their 11th EuroLeague championship despite missing several key players due to injuries and suspensions.

[8] He also led Madrid to a 3–0 win in the 2024 ACB playoff final series against UCAM Murcia, reclaiming the Spanish league title for Los Blancos after a year off.