Russ hit Robinson to make the score 17-7 with 13:48 left in the third quarter. Russ finished 9 for 19 and 162 yards, connecting with Robinson four times for 85 yards.
Though Mercer (4-5, 1-4 Southern Conference) was outgained 417-335, Chattanooga (7-2, 5-1) hurt itself with four turnovers.
Chattanooga's Jacob Huesman was 15 for 21 for 197 yards with two interceptions. Huesman carried the ball 24 times for 112 yards and had both rushing touchdowns for the Mocs. Their last two drives ended with Wil Young's fumble and Huesman's second pick.
Russ' 1-yard run put Mercer up 7-0 near the first quarter's end. Huesman then orchestrated a 13-play, 82-yard drive to even it after his 1-yard plunge.
Jagger Lieb's 19-yard field goal before half put the Bears on top for good.