After UEFA investigated a fan's Nazi salute, Atlético Madrid has been ordered to close a 5,000-seat section of its stadium when it hosts Manchester City on Wednesday.
The fan was filmed making a Nazi-style gesture during Atlético's 1-0 loss at City in the first leg of their Champions League quarterfinal last Tuesday.
UEFA said last Friday it charged the Spanish club with "discriminatory behavior."
On Monday, the next working day, the closure was announced by its appeals body.
The fast-tracked process ensured Atlético serves the sanction in an equally high-profile game against the same opponent, rather than potentially waiting until next season for a group-stage game in a lower-tier competition.
Atlético is fourth in La Liga, just one point ahead of the Europa League qualifying place.
The club must close a section of at least 5,000 seats at Metropolitano Stadium for the second leg and display a UEFA banner there saying "#NoToRacism."
