Gordon made seven consecutive shots from beyond the arc during the second period and hit 8-of-10 long range shots overall while scoring 26 points.
Philadelphia, which went into the game with a chance to finish as the No. 7 seed in the Eastern Conference, wound up in the eighth spot. That will put the 76ers up against Chicago in the first round of the playoffs, a series that will begin Saturday.
Rodney Stuckey contributed 13 points for the Pistons, who won 25 games this season and missed the playoffs for the third straight year. Ben Wallace, who perhaps played for the final time in the NBA, scored seven points for the Pistons.
Spencer Hawes had 16 for the 76ers, who scored only 15 points in the first period and trailed by 22 at halftime.