Jaclyn Amader hit a three-run triple on Sunday against Marshall.
Trailing 2-0 in the bottom of the sixth, Liberty scored four times to overtake Marshall, 4-3, on Sunday at Carolina Softball Stadium at Beckham Field.
Liberty improves to 14-5 on the season after going 4-1 at this weekend's Carolina Classic, while the Thundering Herd falls to 8-11.
Julia DiMartino (4-3) earned the win, allowing three runs on six hits while striking out three.
Abigail Tolbert (3-5) drew the loss, giving up four runs, three earned, on five hits, walking one and fanning one in 5 1/3 innings pitched. Williamson pitched 2/3 of an inning, giving up one walk.
Jasmeen Click batted 2-for-2 for Liberty, while Jaclyn Amader went 1-for-3 with a triple and three RBI.
Marshall's Aly Harrell went 2-for-2 with a homer, one run scored and one RBI.
With Liberty trailing, 2-0, Click bunted for a single to start the bottom of the sixth. Autumn Bishop then reached on an error. A fielder's choice put runners on the corners. Tori Zavodny bounced an RBI single on the infield, slicing the deficit to 2-1. Sarah Robertson then singled to left, loading the bases. Amader sent a bouncer through the hole in between first and second for a triple, scoring all three runners on the play as the ball caromed into foul territory. Williamson came on in relief of Tolbert, getting Deidra See to line into an inning-ending double play.
Harrell lined a solo homer over the wall in right to lead off the seventh, narrowing the deficit to 4-3. The Herd put the tying run on base when Madi Marshall singled up the middle with one out. However, the next two batters both flied out to right, sealing Liberty's win.
The Lady Flames turned 5-4-3 double plays in each of the first two innings, short-circuiting Marshall's run-scoring potential.
Tolbert pitched around a one-out walk to Amader in the second inning, retiring the next two batters to maintain the scoreless tie.
Marshall manufactured two runs with two outs in the top of the third. Jordan Colliflower and Elicia D'Orazio both reached on bunt singles. Eloise Tribolet then beat out an infield single, and Colliflower and D'Orazio both raced home with heads-up baserunning for a 2-0 Herd lead.
Click singled up the middle with one out in the third, but Tolbert got the next two batters on grounders.
Harrell led off the fourth by singling to right. See later threw out pinch runner Rachel Rousseau, who attempted to steal second. DiMartino got Marshall on a popout for the third out.
DiMartino retired the side in order in the fifth and sixth innings, setting up Liberty's comeback.
The Lady Flames return home, and will host the Liberty Softball Classic, Thursday through Sunday at Liberty Softball Stadium. The tournament will begin on Thursday as Liberty takes on nationally-ranked Baylor at 6 p.m.