Question: What decade old football team beat Old Etonians in the Football Association Callenge Cup that marked the turning point in the sport from upper-class gentleman to a professional sport?

Context paragraphs:
1876 FA Cup Final: The 1876 FA Cup Final was a football match between Wanderers and Old Etonians on 11 March 1876 at Kennington Oval in London.  It was the fifth final of the world's oldest football competition, the Football Association Challenge Cup (known in the modern era as the FA Cup).  Wanderers had won the Cup on two previous occasions.  The Etonians were playing in their second consecutive final, having lost in the 1875 final.  Both teams had conceded only one goal in the four rounds prior to the final.  In the semi-finals Wanderers defeated Swifts and the Etonians beat the 1874 FA Cup winners Oxford University.

1878 FA Cup Final: The 1878 FA Cup Final was a football match between Wanderers and Royal Engineers on 23 March 1878 at Kennington Oval in London.  It was the seventh final of the world's oldest football competition, the Football Association Challenge Cup (known in the modern era as the FA Cup).  Wanderers had won the Cup in the previous two seasons and on four previous occasions in total, including the first FA Cup Final, in 1872, in which they defeated the Engineers.  The Engineers had also won the Cup, having defeated Old Etonians in the 1875 final.

1883 FA Cup Final: The 1883 FA Cup Final was contested by Blackburn Olympic and Old Etonians at the Kennington Oval.  Blackburn Olympic won 2–1 after extra time.  Jimmy Costley and Arthur Matthews scored for Blackburn; Harry Goodhart for Old Etonians.  It was a watershed match for the sport, as for the first time in an FA Cup final a working-class team playing the 'combination game' (passing) were triumphant over a team playing the public school tactics of 'rushing' and 'scrimmages'.

Arthur Dunn Challenge Cup: The Arthur Dunn Cup is a football cup competition played between the Old Boys of public schools.  It started in 1903 and is named in honour of Arthur Dunn who had proposed such a competition but died very suddenly shortly after.  Dunn was a leading amateur player of his day and was in the winning Old Etonians side in the 1882 FA Cup Final.  It was Dunn who passed the ball to Anderson who scored the only goal to defeat Blackburn Rovers at the Kennington Oval.

1882 FA Cup Final: The 1882 FA Cup Final was contested by Old Etonians and Blackburn Rovers at the Kennington Oval.  Old Etonians won 1–0, the only goal scored, according to most reports, by William Anderson, although another, questionably, gives Reginald Macaulay.  It was the last final to be won by one of the Southern "gentleman amateur" teams who had dominated the first decade of the competition.

Fantasy sport: A fantasy sport (also known less commonly as rotisserie or roto) is a type of online game where participants assemble imaginary or virtual teams of real players of a professional sport.  These teams compete based on the statistical performance of those players' players in actual games.  This performance is converted into points that are compiled and totaled according to a roster selected by each fantasy team's manager.  These point systems can be simple enough to be manually calculated by a "league commissioner" who coordinates and manages the overall league, or points can be compiled and calculated using computers tracking actual results of the professional sport.  In fantasy sports, team owners draft, trade and cut (drop) players, analogously to real sports.

Football in Singapore: Association football, known more popularly as football in Singapore, is the national sport of the nation.  The sport reached its peak in the 1980s and 1990s during the Singapore Lions' time in the Malaysia Cup, where they dominated the competition.  Singapore is home to the Football Association of Singapore, formerly known as the Singapore Amateur Football Association, the oldest football association in Asia, its roots coming from The Football Association, in England.  The nation's national teams include the men's, the women's and the boys'.  The Singapore Lions, the team which plays in the Malaysia Cup, is not counted due to the team being more like a club, since there is the allowance of foreign players or transfers in the team, and the Malaysia Cup being a club competition among Malaysian states and Singapore.

1874–75 FA Cup: The 1874–75 FA Cup was the fourth season of England's oldest football tournament, the Football Association Challenge Cup or "FA Cup".  29 teams entered, one more than the previous season, although four of the 29 never played a match.  The final was contested by Royal Engineers – playing in their third final in the four seasons of the FA Cup – and Old Etonians – playing in their first final.  On their way to the final, Royal Engineers knocked out Cambridge University in the Second Round and holders Oxford University in the Semi-finals, while Old Etonians only managed to score more than one goal in one match: their second replay against Swifts, which they won 3–0.  The biggest win of the competition was recorded by two-time FA Cup winners Wanderers, who beat Farningham 16–0 in the First Round.

Football records in Scotland: Football in Scotland is a popular professional sport.  Founded in 1873, Scotland has the second oldest national football association in the world.  The national cup competition, the Scottish Cup, was started in the 1873–74 season.  Its trophy is the oldest national sporting trophy in the world.  A Scottish football league system was first instituted in 1890, with the creation of the Scottish Football League.  A second national cup competition, the Scottish League Cup, was created in the 1946–47 season.  This page details the team and individual records set in these competitions.

Blackburn Olympic F.C.: Blackburn Olympic Football Club was an English football club based in Blackburn, Lancashire in the late 19th century.  Although the club was only in existence for just over a decade, it is significant in the history of football in England as the first club from the north of the country and the first from a working-class background to win the country's leading competition, the Football Association Challenge Cup (FA Cup).  The cup had previously been won only by teams of wealthy amateurs from the Home counties, and Olympic's victory marked a turning point in the sport's transition from a pastime for upper-class gentlemen to a professional sport.

Supporting paragraphs: 1883 FA Cup Final Blackburn Olympic F.C.
Answer: Blackburn Olympic Football Club