Jan 6, 1951, Indianapolis Olympians at Rochester Royals, Edgerton Park Arena, Rochester, NY (My Social Mate.com)
Yesterday, the Portland Trail Blazers beat the Denver Nuggets 140-137 in a four overtime playoff game, only the second quadruple overtime in the postseason and the first since the adoption of the 24 second shot clock.

Rochester Democrat and Chronicle, Jan 7, 1951
Actually, the longest game in NBA history was on January 6th, 1951 when the Indianapolis Olympians defeated the Rochester Royals in a six overtime game played at Edgerton Park Arena. In fact, that game was one of three NBA historical milestones that all happened in Rochester.

Box score from Earl Lloyd’s first game. Rochester Democrat and Chronicle, November 1, 1950 From When NBA history was made at Edgerton Park
As seen in When NBA history was made at Edgerton Park, on October 31st, 1950 Earl Lloyd became the first black player in the NBA.

During the inaugural season of the new rule, the Royals advertised its pleasurable appeal. Rochester Democrat and Chronicle, 20 Nov 1954 From Remembering one of two NBA firsts in Rochester: the 24 second shot clock. And why it was bad.
As seen in Remembering one of two NBA firsts in Rochester: the 24 second shot clock. And why it was bad., almost exactly four years later fans at Edgerton Park Arena saw the first use of the 24 second shot clock.
As described in When Rochester Was Royal: Professional Basketball in Rochester 1945-1957 (the website for a 2016 exhibit at Rochester Institute of Technology), the Royals played in Rochester from 1945 to 1957 and won the NBA championship in 1951.
Unfortunately, as noted in “Exhibit celebrates Rochester Royals team” (RIT News, March 29, 2016):
The team was studded with future hall of famers including Arnie Risen, Al Cervi, Bob Davies, Red Holzman, Maurice Stokes, Jack Twyman and Bobby Wanzer.
(left) The New York Times, 4/21/20; (right) NBA 1951 Finals action: Arnie Risen grabs a rebound over Harry Gallatin as Jack Coleman (10) and Vince Boryla (12) look on. (goldenrankings.com/NBAFinal1951)
Despite the players, owner Les Harrison—one of the most energetic and dedicated owners in league history—loyal fans in an affluent city and an NBA championship, the Royals could not remain in Rochester.

Sports and the American Jew (1998) edited by Steven A. Riess includes a chapter, “Lester Harrison and the Rochester Royals, 1945 – 1957: A Jewish Entrepreneur in the NBA” [Held at the Feinbloom Library, Jewish Community Center] From The Jewish Sports Hall of Fame at the Jewish Community Center in Brighton