Auerbach retired as coach after the 1965–66 season and Russell took over as player-coach, which was Auerbach's ploy to keep Russell interested. With his appointment Russell became the first African-American coach in any U.S. pro sport. Auerbach would remain the general manager, a position he would hold well into the 1980s. However, the Celtics' string of NBA titles ended when they lost to the Philadelphia 76ers in the 1967 Eastern Conference Finals. The aging team managed two more championships in 1968 and 1969, defeating the Los Angeles Lakers each time. Russell retired after the 1969 season, effectively ending a Celtics dynasty that had garnered an unrivaled 11 NBA titles in 13 seasons. The team's run of 8 consecutive is the longest championship streak in U.S. professional sports history.