Cassie Whitworth's ice cold, three-bomb with four seconds left tied the contest for FMS, but the upset attempt was spoiled on a last second, game winning lay-up by Liberty's Olivia Doak.
The Lady Patriots took an early 8-2 lead before Whitworth drilled a three-pointer to make it 8-5, but that would be the last score for FMS in the opening period as they trailed 10-5 after the first six minutes.
Doak and FMS seventh-grader Caitlin Yost swapped buckets, keeping the one-point Liberty lead.
Forrest fell behind by four points at 17-13 before Yost scored, but a late basket by Liberty's Ashley Neeley made it 19-15 at the half with the Bedford County squad in the lead.
It did not look good for the Lady Rockets in the second half as they were outscored 8-5 in third period and trailed by seven 27-20 entering the final six minutes of play.
With just over two remaining in the contest, FMS trailed by nine points 36-27 before a furious comeback got underway.
The Lady Rockets turned up the pressure defense, resulting in a series of turnovers for Liberty.
In the process, Tamia Northcut hit on one of two from the free throw on two separate occasions to make it a 36-29 with 1:36 left when FMS head coach Jeremy Jean called timeout.
Moments later, Yost scored in the paint to cut the lead five before another Liberty turnover, caused by Forrest pressure in the backcourt gave the rock back to the Lady Rockets.
Dani Hoeft was fouled by Liberty and the FMS guard stepped to the free throw line and calmly nailed both attempts to make it a three-point ballgame at 36-33.
Liberty coughed the ball up on the ensuing inbounds play with 8.2 seconds remaining.
Jean inserted Whitworth into the game and it paid off when she drilled the game tying three-pointer from deep in the corner.
The Lady Patriots brought the ball up and called timeout to set up a play that went to Doak for the game winner with 3.3 seconds left.
Forrest could not get a shot off as the clocked ran to all zeros.
Doak led all scorers with 18 points.
Collins led a balanced Lady Rocket scoring attack with 9 points, Whitworth and Yost netted 6 apiece, Northcut had 5, Colvin ended up with 4 points, and Taylor Patin, Amanda Patterson and Hoeft all finished with two markers each.