The constant downpour hampered passing as both teams combined for 98 yards in the air. Jared Johnson completed 7 of 13 passes for 63 yards and the first two touchdowns for the Bearkats (5-2, 5-1 Southland).
Seven Bearkats ran the ball 55 times for 310 yards and three touchdowns. Overstreet opened the second quarter with a 12-yard TD run. His 200 yards was a career best at Sam Houston after transferring from Texas in 2013.
Tuskani Figaro put Nicholls (1-6, 1-4) on the board with an 80-yard run around left end in the third quarter. He completed 6 of 20 passes for 35 yards.
The Bearkats, with the top scoring offense in the FCS, has outscored its last five opponents 242-77.