The Sixers last lost 20 consecutive games from Jan. 9, 1973-Feb. 11, 1973 during a 9-73 campaign. The NBA record for most losses in a row is 26, set by the Cleveland Cavaliers in 2010-11.
Philly hasn't won since Jan. 29 at Boston.
Zach Randolph added 14 points for the Grizzlies, who have won five of their last six games.
Michael Carter-Williams tallied 23 points and eight rebounds, while Thaddeus Young registered 20 points, seven boards and six steals for the Sixers.
The Grizzlies held a 22-21 advantage after a quarter of play and the game was tied 22-22 early in the second before Memphis used a 13-2 run to seize control of the contest.
Memphis led 45-36 at the break and pulled away even further following a 15-3 swing during the early stages of the third. Tayshaun Prince finished off the burst with a hook shot as the Grizzlies opened up a 62-42 gap.
The Grizzlies took a 74-57 cushion into the fourth, where they led by as many as 29 before cruising to the easy win.