Freshman Savannah Brothers scored 12 points for Forrest, tying Middle Tennessee Christian School duo Julia Howard and Meghan Smith for game-high scoring honors in the Lady Rockets' triumph.
The Lady Rockets led 12-10 after the first quarter and built their lead to 21-14 at the half, before the Lady Cougars clawed their way back to tie the ballgame by the end of the third quarter, thanks to 15-8 margin in the period.
Also avenging an earlier season loss to the Lady Cougars in Chapel Hill, Forrest held firm in the final period, outscoring the home team 13-9 to improve to 11-11 on the season and 7-4 in District 9-A play.
The Lady Rockets remained tied for second place with Eagleville (12-9, 7-4), but Forrest holds the tiebreaker with a sweep of the regular season series over the Lady Eagles.
Hannah Phifer was second in the Forrest scoring column with nine points, Tayler Andrews and Candace Daughrity scored seven points apiece, Kirston Holder netted three, and Adrean Jordan and Hannah Evans finished the game with two markers each.
MTCS (13-9, 6-5) dropped to third place in district action, tied with a (14-8, 6-5) Cascade team that visits Chapel Hill Friday night, beginning at 6 p.m.
The Rockets' win was a big one, clinching one of two top spots in the upcoming district tournament, beginning Feb. 10 and running thorough the 17th at MTCS.
The first-place Rockets and second-place Community Vikings are tied at 10-1 in district play with a showdown looming at Forrest on Feb. 3.
Tyler Rumley backed up his strong performance versus Moore County with a 12-point effort versus the Cougars, Zach Horvath pitched in with a half dozen in the hole, Lucas Pruitt banged in five points, and point guard Colby Anglin and Zach Ray posted four points apiece.
Forrest came out strong, putting up 18 points to the Cougars' 11 in the first quarter, before proceeding to lead by nine, 35-26 at the half.
MTCS staged a furious second-half comeback, beginning the third period with a one-point (16-15) advantage.
In the fourth quarter, the Cougars kept the pressure on the visiting Rockets, but a 19-13 bulge was not enough as Forrest withstood the barrage to win by the two-point margin.
MTCS' Micah Farmer led all scorers in the contest with 27 points, Ben Brown netted 19, Derrick Spears was also in double figures with 10, and Ty Hageman rounded out the night's scoring with three points.
After the Friday night battle with the Champions in Chapel Hill, Forrest packs up the yellow bus for a Saturday night fight at Summertown, beginning at 6 p.m.