Partizan Belgrade have been fined and forced to play their next Europa League match in a partially closed stadium after their fans displayed an anti-Semitic banner against Tottenham.
The flag was an imitation of the logo from BBC comedy show Only Fools and Horses, with some words modified to form an offensive slogan.
Uefa said: "The fight against racism is a high priority.
"The fight has been stepped up a level - resulting in stricter penalties."
Partizan will have to close the 'K' section of their stadium when they face Besiktas on Thursday 23 October and have also been fined £31,430 (40,000 euros).
Tottenham officials made Uefa aware of the banner before the break and delegates took photographic evidence after the match.
Spurs have a historical association with London's Jewish community.
In 2007, Partizan were thrown out of the Uefa Cup and fined for rioting during a first qualifying round first-leg clash at Zrinjski Mostar.
And it was in Serbia two years ago that Tottenham left-back Danny Rose, who did not travel with the Spurs squad for the Europa League tie, was subjected to racial abuse while on England Under-21s duty.