Mossman (2-0) allowed just a third inning and a double down the left field line to start the ninth in tossing the complete game shutout.
In his first start of the season, Mossman struck out six, walked two and was the beneficiary of two double plays by the Shenandoah (7-2, 5-1 ODAC) defense.
SU gave Mossman all of the offense he would need with a single run in the third before adding one in the fifth, two in the sixth, one in the seventh and fourth in the eighth off the Generals (3-4, 1-3).
Sophomore John Wilt, who was one of four Hornets with two hits in the game, drove in what proved to be the game-winning run with a one-out groundout to third.
Wilt then hit a chopper to the left of W&L third baseman Ryan Weston and Weston, playing in, elected to take the out at first rather than attempt to cut Pardo down at the plate.
Michael Paul drove in the second run with a single to right in the fifth before he capped his day by drawing a bases loaded walk in the eighth.
All four SU runs in the eighth came without the benefit of a hit.
Kyle Tipping (0-1) took the loss for the Generals. He allowed four runs (three earned) on 11 hits and one walk in 6.0 innings of work.
Shenandoah is back in action at home Wednesday at 4 in a non-league game against Catholic.