W. Michigan 70, E. Michigan 55
The third-seeded Broncos (20-11), who led 36-32 at intermission, made 17 of 21 free throws in the second half compared to the seventh-seeded Eagles' 3 of 3.
Eastern Michigan (16-18), which defeated 10th-seeded Northern Illinois and 11th-seeded Miami (Ohio) in the first two rounds, led by six before the Broncos closed the first half with a 13-3 run.
Western Michigan pushed the lead to 10, but the Eagles climbed back to 50-49 on Jamell Harris' dunk with 8:31 left.
The Broncos then used an 8-0 spurt to end the threat.