Austin Daye had 14 points for Toronto, which is 4-0 when scoring 100 points.
Ed Davis had 11 points and nine rebounds and Jerryd Bayless, another former Raptor, scored 10 for the Grizzlies, who had won three straight against NBA opponents and four in a row overall. Memphis beat Israel's Maccabi Haifa on Oct. 13.
Memphis shot 6 for 21 from the field in the first quarter and trailed 27-14. The Grizzlies were even worse in the second quarter, making only five of 21 attempts. The Raptors closed the half with a 10-0 run to lead 54-27.
Toronto guard Kyle Lowry (left ring finger) was forced out with 3:47 left in the third. Lowry had two points and 10 assists.
Valanciunas had to leave after he was hit in the face by Zach Randolph's elbow with 2:10 left in the third, cutting his chin. Randolph, who was called for a flagrant foul, fouled out on the play. He finished with two points and five rebounds in 25 minutes.
DeRozan made four of five field goal attempts and scored 11 points in the third quarter as Toronto took an 86-50 lead.
Toronto made 24 of 26 free throw attempts and outrebounded Memphis 54-36.
NOTES: Raptors F Steve Novak (right thumb) was not available. ... Toronto concludes its exhibition schedule at Milwaukee on Friday, while the Grizzlies host Houston on Friday night in their final exhibition game. ... Former Raptors guard Haywoode Workman was part of the officiating crew.