 Complete the following phrase:  FK Partizan is a professional football club based in Belgrade, Serbia. Founded in 1945, they were the first Yugoslav and Serbian club ever to enter European competition, playing the European Cup in the 195556 season. They opened the competition in a match against Sporting Clube de Portugal on 4 September 1955. They also became the first club that was not from Western Europe to play in the European Cup final, losing by Real Madrid in 