Dunn became the first Bison player to score four touchdowns since DJ McNorton's effort at Montana State in 2010 in the second round of the FCS playoffs.
Dunn did all his damage in the first half on three carries for 111 yards and three touchdowns and caught a 10-yarder for a score. He scored on runs of 61, 5 and 45 yards.
North Dakota State (3-0) scored five touchdowns in the first quarter and led 49-0 at halftime. The Bison piled up 450 yards of total offense to 57 for Robert Morris (2-2).
The Bison were 10 of 17 on third down conversions with Robert Morris going 0 for 9. The Bison held the ball for just more than 39 minutes.
Cole Blake had 50 yards rushing for Robert Morris.
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