The 1988 Football League Second Division play-off Final was an association football match contested between Chelsea and Middlesbrough over two legs on 25 May 1988 and 28 May 1988. It was to determine which club would play the next season in the First Division, the top tier of English football. Chelsea had finished the season fourth from bottom in the First Division, while Middlesbrough were third in the Second Division. They were joined in the play-offs by the teams that had finished fourth and fifth in the Second Division: Chelsea defeated Blackburn Rovers in their play-off semi-final, while Middlesbrough beat Bradford City. The first leg of the final was played at Ayresome Park in Middlesbrough, in front of a crowd of 25,531. Trevor Senior and Bernie Slaven scored for Middlesbrough, who won the match 2–0. Three days later, at Stamford Bridge in London, 40,550 fans watched Chelsea beat Middlesbrough 1–0. Gordon Durie scored the only goal of the match, but it was not enough for Chelsea, who lost the tie 2–1 on aggregate. Middlesbrough were promoted to the First Division where they remained for one season before they were relegated. Chelsea won the Second Division the following season and, , remain in the top tier of English football. After the final whistle, a few hundred Chelsea fans broke onto the pitch and threw projectiles at the visiting supporters. It took the police around 40 minutes to clear the pitch and the terraces, and 45 people were injured, including 25 police officers. In total, 102 arrests were made, and Chelsea were later found guilty of failing to control their supporters. They were given a £75,000 fine and had to close their terraces for the first six matches of the subsequent season. Background English Football League play-offs were first introduced to determine promotion and relegation between the First and Second Divisions, the top two tiers of the English football league system, in the 1986–87 season. They were a means of reducing the number of teams in the First Division from 22 down to 20, but were also designed to add excitement to the end of the season, giving more teams something to compete for, while also generating more money for those clubs involved. For the first two seasons, they featured three teams from the Second Division, along with one from the First Division. The bottom three clubs from the First Division were