The two setbacks sent Forrest (2-4-2) reeling, all the way to sixth place in the final regular season standings.
Summit looked like the team fighting for home field advantage in the first round as they came out on Thursday and held the Lady Rockets captive in their own end of the field for the first 30 minutes of the contest.
Two-thirds into the half, the Lady Rockets finally got some offense churning as Camille Harris had a good run on a long ball, but Summit goalie Kayla West thwarted the scoring attempt on a sliding tackle.
Moments later, West came out again to barely cut-off a speeding Ciara Cook to a loose ball for another save as the first half went to extra time.
Just prior to the whistle sounding for the halftime break, the Lady Spartans made it 2-0 on an unassisted goal by Katrina Rice, who found some open space after putting some nice moves on the Forrest defenders on the way to the score.
The Lady Rockets met at halftime and decided that they would not go down without a fight and it was Forrest, who came out as the aggressors in the final 40-minutes of play.
Cook cut the Lady Spartans' lead in half at the 33:35 mark when she took a left-footed crossing pass from fellow senior Brittney Hill and found the back of the Summit net past a diving West.
After the Cook goal, Horton got into the act with two nice saves, preserving the one goal margin.
The action was a back and forth affair from that point on and Summit had a great chance to increase their lead on a penalty kick at the 13:37 mark, but Rice's boot sailed wide.
Hill had a good chance with just over eight minutes left, but could not capitalize and then at the 2:20 mark, Cook looked like she would tie the game when she broke loose behind the Summit defense, but West came out and both players collided on a hard, clean hit.
West came up with ball as both players lay injured on the field.
Cook, who eventually returned to the pitch, had to come out after the collision and West was hobbling the remainder of the contest.
There were no more scoring chances for the Lady Rockets, who ended up in sixth place and a date at Cascade (3rd place) on Friday at 4:30 p.m. in the first round of the district tournament.
Marshall County (8th place) will host Cornersville (9th) Thursday at MCHS in a play-in game.
The winner gets the pleasure of meeting the number one seeded and undefeated Page Lady Patriots in round one next Tuesday.
Summit (4th place) will host MTCS (5th place) and the Community Viqueens (2nd place) will entertain Huntland (7th place) in round one.
The semifinals and finals will be held at Page, beginning on Tuesday, October 18 at 5:00 p.m.