Damier Pitts scored 20 points and Marshall defeated SMU 73-68 on Saturday.
Three other Thundering Herd players were in double figures. DeAndre Kane had 14 points, Nigel Spikes scored 13 and Dennis Tinnon added 12 points for Marshall (16-10, 7-5).
The Thundering Herd never trailed and led by as many as 20 with just over 10 minutes left before the Mustangs rallied, but they couldn't get closer than four points.
SMU (11-16, 2-10), coming off the lowest point total ever in a Conference USA game in Wednesday's 47-28 loss to UAB, also started poorly on Saturday with just 14 points in the first half. SMU scored 39 points in the last 10 minutes on Saturday.
London Giles, who missed the UAB game due to a concussion, returned Saturday and led the Mustangs with 17 points. Jalen Jones scored 13 of his 15 points in the second half.
