 Complete the following phrase:  These achievements prompted the switch to professional football, which occurred in 1964, concurrently with the extension of membership from the Southern Football League. Wimbledon finished second twice out of the teams first four outings in this competition, before again winning three consecutive titles from 1975 to 1977. The club won election to The Football League after these successes, and thus entered the Fourth Division for the first time in 197778. Wimbledon took only ten seasons as a Football League club to reach Englands top flight, winning promotion to the First Division for the 198687 season; Wimbledon then beat League champions Liverpool 10 in the 