Yaw, a freshman, also had kicks of 35 and 27 yards.
The Bulldogs (3-2, 1-1 Southern Conference) had 163 yards rushing, while holding the Catamounts (0-5, 0-3) to just 48.
Bryce Smith had nine tackles and an interception, Ty Levie recovered a fumble and Corey White also had an interception for Samford.
Chris Evans led the Bulldogs with 140 yards and a touchdown on 26 carries. Dustin Taliaferro was 12-for-24 for 103 yards for Samford.
Zack Jaynes was 12-for-19 with 115 yards and two interceptions for Western Carolina. Jaynes also had 12 carries for 20 yards.
Blake Bostic hit a 44-yard field goal for Catamounts with 5 minutes left in the first half.