The Raiders (2-2) scored on a safety when the first blocked punt went out of the end zone. Steffen's second block off FCS Punter of the Week Harry McCollum was returned 10 yards for a score by Pat Afriyie. Steffen, a defensive lineman, also had three tackles for loss, including a 17-yard sack.
Quarterback Jake Melville scored on a 38-yard run with 40 seconds left in the half for a 16-0 lead. Jonah Bowman added a fourth-quarter field goal.
Melville ran for a career-high 128 yards on 14 carries, part of Colgate's 319 yards rushing, for his third straight game rushing for over 100 yards.
The Hoyas (2-3) managed only 35 yards rushing. Kyle Nolan completed 15 of 28 passes for 128 yards.
It was the first shutout for Colgate since it blanked Fordham in 2005.