Shenandoah (33-5) scored three runs in the first, three more in the second and two in the third to get itself a comfortable lead over the Yellow Jackets (21-18).
After SU scored those three runs on the first (on just one hit), R-MC touched SU starter Greg Van Sickler (10-1) for four runs on four hits in the second.
Jordan Walton and James Bierlein both took Van Sickler deep, but the senior All-America rebounded in the final three innings of his 12th start this season.
Van Sickler struck out 11 in 5.0 innings before turning it over to four classmates on Senior Night.
The last of those, Ben Wimmer, pitched to just one batter and got Peter Culver to hit into a game-ending double play.
The appearance was the first of Wimmer's four-year career at Shenandoah.
The Hornets got what proved to be the game-winning runs in the second by seeing their first three hitters reach base safely. Mike Smith led off with a double before Bryan Claudio beat out an infield single for his first career hit.
In between, Claudio gave SU the lead for good by scoring on a wild pitch.
Both teams had 10 hits on the day with Krout leading the victors with three hits in four at-bats.
Clint DeHaven also had a home run, a two-run shot in the first, for the hosts.
Walton, Bierlein and Cory Jackson had two hits each for Macon.
Shenandoah will wait until May 15 to see about a possible Pool C berth into the NCAA Tournament.
Notes: It was Senior Night and the Hornets started seven starters in the nine positions (Van Sickler hit for himself for the first five innings. Ten of the 11 seniors saw action with only pitcher Ben Hendrickson (who pitched yesterday) not appearing. It was the first action this season for Claudio and Wimmer and the first field play for Roberson.