What is Derby County's biggest win?

Derby County Football Club is an English professional football club based in Derby, Derbyshire. It has a long and illustrious history, and has been a member of the Football League since it was founded in 1884. One of the club's biggest wins came in 1975 when they beat Liverpool 3-1 in the FA Cup Final. This was one of the most remarkable victories in the club's history as they had just been promoted to the First Division only a year before. The victory was even more remarkable as Derby County was an unfancied team, while Liverpool had won the title four times in the previous five seasons.

The match itself was a thrilling affair and Derby County went behind early on when Liverpool's Kevin Keegan scored a penalty. However, Derby County equalized soon after and then took the lead in the second half when Roy McFarland scored a stunning goal. The match was sealed in the dying moments of the game when Archie Gemmill scored a stunning goal to give Derby County their first major trophy for more than a century.

Derby County's victory over Liverpool was a significant moment in the club's history and it was the first major trophy for the club since their FA Cup victory in 1898. The victory provided a huge boost in confidence for the club and was one of the key moments in their history. It also helped to elevate Derby County's status in the game and show that they were capable of competing at the highest level.