Shenandoah (13-4, 3-2 ODAC) was an 8-1 winner in game one before taking game two 8-7 in 10 innings over the Quakers (11-11, 2-5).
Senior Phillip Morse (2-0), who pitched the final 2 2/3 innings, got the win as he stranded a pair of runners in the bottom of the frame.
SU banged out 13 hits in the opener and got a six-hitter from senior Darrell Thompson in coasting to the victory.
Coach Kevin Anderson's club scored one run in the first and three more in the third to provide Thompson (3-1) all of the offense he would need.
Thompson allowed one run on six hits and one walk in 7 2/3 innings of work. The southpaw had three strikeouts before turning it over to classmate Ryan Mossman for the final four outs.
Mossman struck out one in retiring all four batters he faced.
Wilt keyed the four-run ninth with a three-run blast to right.
Eight of the nine hitters in the SU lineup had at least one hit.
Guilford touched game two starter Michael Scimanico for four runs on four hits and two walks in the fourth, but Shenandoah answered with three in the top of the fifth to knot the contest at 4-4.
GC sandwiched one run in the fifth and two in the eighth around a three-run SU seventh to send the game into extras.
Wilt was 4 for 5 with three RBI to lead the game two offense.
Shenandoah continues ODAC play with a 4 p.m. Tuesday contest against Bridgewater.