On 1 September 2019, Partey came on as a late substitute and netted the match's winner in the last minute of the game, as Atlético came back from 2–0 down to win the game by 3–2 against Eibar. He marked his 100th La Liga appearance for "Los Rojiblancos" with a man-of-the-match performance in a 0–0 draw against Real Madrid in the Madrid derby four weeks later. Despite leaving Atlético at the beginning of the 2020–21 season, Partey made enough appearances at the start of the season to become eligible for a winner's medal as Atlético won La Liga that year.