FAMU (4-18) finished the contest with nine hits as John Scott went two-for-four from the plate to lead the Rattlers.
Mercer (16-7) tallied 14 hits as Chesny Young went three-for-five from the plate to lead the Bears.
Dimitri Kourtis (4-0) picked up the win for Mercer as he pitched two innings of relief, giving up one hit and striking out three. Heath Blackburn (1-4) received the loss for FAMU as he gave up five hits and five earned runs in three innings of work.
Mercer grabbed a 2-0 lead as Evan Boyd scored on a Nick Backlund ground out to the pitcher. Then Nate Moorehouse would score on an Austin Barrett sacrifice fly to centerfield, in the bottom of the first.
FAMU would cut the Mercer's lead to 2-1 as Daniel Lee scored on a Michael Birdsong ground out to third, in the top of the second inning.
The Bears would then score four runs in the bottom of the third to take a 6-1 lead.
FAMU cut Mercer's lead to 6-4 as Lee scored on Birdsong single, followed by an Aaron Smith single scoring both Birdsong and Justin Abney in the top of the fourth inning.
Mercer would score seven more run as they scored three runs in the fourth, one in the fifth and three in sixth, while FAMU pushed across one run in the top of the seventh innings for the 13-5 final.
The Rattlers will return to action on Saturday, March 24 as they host Jackson State in a nonconference doubleheader at Moore-Kittles Field with the first pitch slated to be thrown at 1 p.m.