Sibande was 5 of 11 from the floor, and 11 rebounds and made all five of his free-throw attempts.
Bowman made 3 of 6 attempts from 3-point range.
No one scored in double figures for Drake as the defending Missouri Valley Conference champions shot 35.2 percent from the floor.
Miami advances to play South Alabama in the Gulf Coast Showcase semifinals at 5 p.m. Tuesday.
The Jaguars beat Northeastern 74-62 in the opening game of the tournament Monday.
Wright State, Weber State, Murray State and La Salle are also part of the tournament, which is set to wrap up Wednesday night.