Boston's opponents in the 1976 NBA Finals were the Phoenix Suns, who had posted a 42–40 regular-season record. The Team in Green was the oddsmakers' choice in the contest. The Celtics took the first two games at Boston Garden, but the Suns came back to win games 3 and 4 on their home court. Game 5 ranks among the all-time thrillers in NBA history. The Suns trailed by 5 points with less than a minute left on the clock, but Westphal made up the deficit almost single-handedly, sending the game into a first overtime period, which ended in a tie.
John Havlicek's basket with 2 seconds remaining in double overtime gave the Celtics a one-point lead, which Boston stretched to two points after sinking a technical foul. Then the Suns' Garfield Heard hit a last-second basket to send the contest into a third overtime. The longest game in NBA history finally ended, after three extra periods, with the Celtics winning 128–126. Two days later Boston captured yet another NBA championship, the 13th in franchise history.