In an effort to lessen the dominance of big men and keep the game open and moving, the NBA widened the foul lane from 12 to 16 feet. A major trade that took place at the NBA All-Star break would have far-reaching implications for years to come. Wilt Chamberlain, in the midst of his greatness at 28 years old, was dealt by the San Francisco Warriors to the Philadelphia 76ers for Paul Neumann, Connie Dierking, Lee Shaffer and cash. The immediate results: San Francisco went from 48-32 the season before to 17-63, while Philadelphia improved from 34-46 to 40-40. More importantly, Chamberlain was back in the Celtics' division, and would have to be dealt with even before the NBA Finals.

John Havlicek and Jerry West went head-to-head in the 1965 Finals.

Meanwhile, Celtics founder Walter Brown died in August, 1964, putting more of the team's administrative load on Auerbach. Boston seemed unaffected, however, and broke its own league record with 62 victories despite the retirements of Frank Ramsey and Jim Loscutoff. The Lakers won the West with 49 wins as West (31.0) and Baylor (27.1) finished in the top five in the league in scoring. While the Lakers defeated Baltimore in six games in the West Finals, the East Finals between Boston and Philadelphia was a classic, with the home team winning each of the first six games. Boston won Game 7 by a point, with John Havlicek's deflection producing the famous "Havlicek stole the ball!" radio call from Celtics broadcaster Johnny Most. The Finals were less exciting, with Boston closing out the Lakers, who were without the injured Elgin Baylor, in five games.

The seventh game of the Eastern Division Finals in 1965 provided some hope for the rest of the league that the Celtics might be beaten one day soon. If Philadelphia had been able to convert in the last five seconds, the Celtics dynasty would have been halted at six straight NBA Championships and Chamberlain and the 76ers might have begun their own dynasty.

But Havlicek deflected the inbounds pass of Hal Greer to Sam Jones, who dribbled out the five seconds and preserved the dynasty for another year. Of such momentous plays are titles won and lost, and for now, the Celtics were still on top.