One of Pflieger's four 3-pointers capped a 12-0 Rice run to start the second half and give the Owls a 46-21 lead. Rice (2-2) held North Florida (0-4) scoreless for nearly eight minutes during that stretch.
Rice scored 11 3-pointers. Foster had three, Connor Frizzelle two and Bryan Beasley hit one of his two during a 14-3 run in the first half.
Rice recorded assists on 21 of 25 field goals. Ten Owls finished with at least one assist.
Cortez Riley scored 12 points and Cameron Lovelace had 11 to lead the Ospreys.
The win was the second for Rice in three games at the tournament.
North Florida was winless, losing three games by an average of 30 points.